By
Dr. Nitish Priyadarshi.
Fig: The above pictures are of Surajkund area in Hazaribag district in Jharkhand.Rocks of Jharkhand State in India which are mineral rich can also be used for trapping Helium deposit. In Jharkhand helium has been reported in the gases of different thermal springs of Hazaribag district.
In Jharkhand, concentration of helium is highest in thermal gases of Surajkund (3.63 mole %) followed by Charhi (3.38 mole %), Duari (2.95 mole%), Barkagaon (0.29 mole %)and Badam (0.09 mole %). Surajkund hot spring (also called Surya Kund) is a natural hot spring in Belkapi gram panchayat of Barkatha community development block in Barhi subdivision of Hazaribag district in the Indian state of Jharkhand.
Mineral radioactivity plays an important role in the natural occurrence of helium. Helium is an end product of radioactive decay. Helium is also known from the damp of many coal mines. The release of helium from rocks/minerals is greatly promoted by leaching with H2 , CH4 and its homologues. In this area high helium seems to have originated from the combination of the above processes.
According to other report, two well-known groups of thermal springs at Bakreswar (West Bengal) and Tantloi (Jharkhand) give-off substantial quantities of helium-bearing natural gases as bubbling emanations. These two thermal spring sites are located 25 km from
each other and about 250 km from Kolkata. In Tantloi the presence of helium in gases of thermal spring is 1.26 vol. %.
Helium is used for many purposes that require some of its unique properties, such as its low boiling point, low density, low solubility, high thermal conductivity, or inertness. Of the 2008 world helium total production of about 32 million kg (193 million standard cubic meters) helium per year, the largest use (about 22% of the total in 2008) is in cryogenic applications, most of which involves cooling the superconducting magnets in medical MRI scanners.
Helium is extracted in Poland, Russia, China, Algeria, Canada and the Netherlands. The average concentration of helium in fields of these countries ranges between 0.18 and 0.9 vol%. Since such favourable natural gas deposits are not found in India, it seems logical to look for them in unconventional terrestrial sources such as thermal spring emanations and monazite sands.
A thermal spring is the manifestation of extremity of an ascending hot fluid column, which pierces successive layers of the lithosphere and comes forth through the vents. It issues along fractures and fissures, which are invariably linked with deep-seated faults in well-defined zones of mechanical weakness. There are nearly three hundred thermal springs scattered all over India. Preliminary estimation performed by Variable Energy Cyclotron Centre (VECC), Department of Atomic Energy (DAE) at Bakreswar, District Birbhum, West Bengal reveals that quite a number of thermal springs emit natural gases containing helium in significant measure.
Three distinct belts of thermal springs so far identified in India by the Geological Survey of India are: (1) Eastern India – Jharkhand, Assam and Orissa; (2) West coast of India – Ratnagiri, Thane, Colaba and Surat, and (3) Himalayan Belt – Jamunotri (Uttaranchal), Gangotri and Monikaran (Kullu Valley, Himachal Pradesh).
Earlier, radon, helium and uranium measurements have been carried out in hot water springs in the Parbati and Beas valleys of Himachal Pradesh in India. Most of these hot springs are known as famous pilgrimage centers. The activity of dissolved radon in the liquid phase is found to vary widely, by an order of magnitude, between 10 and 750 Bq L−1, whereas, the dissolved helium content in these thermal springs varies between 10 and 100 ppm. The uranium contents are low and vary from <0.01 to 5 μg L−1. The measured values of radon, helium and uranium are possibly controlled by structural geology, namely the presence of pervious fault systems, and by the lithology of the leached host rocks.
Helium is found in large amounts in minerals of uranium and thorium, including cleveite, pitchblende, carnotite and monazite, because they emit alpha particles (helium nuclei, He2+) to which electrons immediately combine as soon as the particle is stopped by the rock. In this way an estimated 3000 metric tons of helium are generated per year throughout the lithosphere. In the Earth's crust, the concentration of helium is 8 parts per billion. In seawater, the concentration is only 4 parts per trillion. There are also small amounts in mineral springs, volcanic gas, and meteoric iron. Because helium is trapped in the subsurface under conditions that also trap natural gas, the greatest natural concentrations of helium on the planet are found in natural gas, from which most commercial helium is extracted.
We believe that exploitation of the existing natural gas reserves in India could meet the requirement for domestic consumption of Grade-A helium. This, in turn, would ensure a reliable supply of helium for sustainable development and application of cryogenic technology. Taking into account the growing demand of cryogenic technology in our country, helium concentration assessment of helium reservoir may be undertaken in the Jharkhand state to see if helium can be mined. A detail exploration is needed to improve the database for assessing and evaluating the helium potential in Jharkhand State. Geological Survey of India along with state government and other national agencies will have to play a key role.
Reference:
Priyadarshi N. 2002. Potential of geothermal energy in Jharkhand State, India: Proceedings of the 1st conference and exhibition on strategic challenges and paradigm shift in hydrocarbon exploration with special reference to Frontier Basins. Mussoorie, India, v2, p. 261-265.
Singh, R., and Bandyopadhyaya, A.K., 1995. Geochemical studies of some thermal springs in Hazaribag district, Bihar, India: Indian Minerals, v49, no.1 & 2, p. 55-60.
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