Arunachal Pradesh, considered a sleeping hydropower giant, could be India’s prime producer of vanadium, a high-value metal used in strengthening steel and titanium.
Exploration being carried out by Geological Survey of India (GSI) has placed the eastern Himalayan State on the vanadium map of the country and geologists are confident of identifying a deposit soon.
India is a significant consumer of vanadium but is not a primary producer of the strategic metal. It is recovered as a by-product from the slag collected from the processing of vanadiferous magnetite ores (iron ore), GSI officials said.
According to data provided by GSI, India consumed 4% of about 84,000 metric tonnes of vanadium produced across the globe in 2017. China, which produces 57% of the world’s vanadium, consumed 44% of the metal.
“We found promising concentrations of vanadium in the palaeo-proterozoic carbonaceous phyllite rocks in the Depo and Tamang areas of Arunachal Pradesh’s Papum Pare district. This was the first report of a primary deposit of vanadium in India with an average grade of 0.76% V2O5 (vanadium pentoxide),” a GSI specialist said.
Vanadium mineralisation in Arunachal Pradesh is geologically similar to the “stone coal” vanadium deposits of China hosted in carbonaceous shale. This high vanadium content is associated with graphite with fixed carbon content of up to 16%.
Geologists discovered two bands of about 7-metre thick carbonaceous phyllite for a length of more than 6 km in the Depo area. This prompted the GSI to extend its search to other areas of the State.
“Good prospects” of vanadium for a cumulative length of 15.5 km and an average thickness of 7m were found in the Deed, Saiya and Phop areas of Lower Subansiri district. Vanadium content was also found in the Pakro area of Pakke-Kesang district, Palin-Sangram in Kra Daadi, Kalamati in West Siang, Kalaktang in West Kameng and Kaying in Siang district.
“The expected grade of vanadium mineralisation in Arunachal Pradesh is comparable to the important vanadium deposits of the world. The largest deposits are in China, followed by Russia and South Africa,” the specialist said.
Vanadium in its pure form is a soft, grey and ductile element primarily derived from mined iron ore, carbonaceous shale or phyllites and steel slag. According to the Indian Bureau of Mines (2018 database), the total estimated reserves or resources of vanadium ore is 24.63 million tonnes, with an estimated V2O5 content of 64,594 tonnes.
Vanadium alloys are durable in extreme temperature and environments, and are corrosion-resistant. Its addition improves the tensile strength of steel and of reinforcing bars used for buildings, tunnels and bridges.
Apart from increasing fuel-efficiency in automotive and aviation industries due to its high strength-to-weight ratio, the metal forms the integral part of vanadium redox batteries that have the least ecological impact in energy storage.
“The global demand for vanadium has been skyrocketing but there was a deficit of 17,300 metric tonnes between demand and supply in 2017. The vanadium find in Arunachal Pradesh could help boost the local and national economy,” the GSI specialist said.