Date | Nov 25, 2015: Area-wise Rajasthan is largest state in India with varied geographical features. Major part i.e. 61% area is covered with desert or semi desert including 11 districts. Climate in this part is dry with scanty rainfall. Despite these negative aspects nature has been very kind to this state in the sense that it has showered state with rich mineral wealth.
State is at par with other mineral rich states like MP, Karnataka, AP, Chattisgarh, Jharkhand. Total 79 minerals are reported out of which 59 are produced commercially in this state. Except high grade iron ore/high grade coal all other minerals are found here. The state government receives Rs. 3000 crores annually as royalty, mining industry gives direct indirect employment to 2 lakh people.
Mineral search is a continuous activity in any country. Central as well as state governments are engaged in mineral survey work. After change in mineral policies now private companies can also go for mining of oil, gold and tungsten. Due to this methodology a private company was able to discover oil & gas in 2004 in Barmer distric area, which shares its border with a neighbouring country. Geologically desert has Mesozoic and younger rock formations.
To a layman rare earth metals could be like any other metal. But to a student of science it means a lot, like the fact that these are a group of 17 elements in periodic table of elements. These elements have been studied in detail like any other chemical research and what we know today is due to scientific research only. General properties of rare metals are that they are silvery to gray in colour, ductile and malleable.
Rare earth elements are used in several high technology industrial products. Their presence in alloys, ceramic and glass compounds and in oxide compounds provide special material properties. In metallurgy, alloying and addition of rare earth elements to steel increase strength and thermal stability. The cracking of petroleum requires catalysts containing various rare earth elements to increase the amount of short hydrocarbon molecules in the product.
In the ceramic and glass industry rare earth elements containing compounds are used for high temperature materials, for coatings, polishing, colouring, decolouring and as glass additives. The main other uses of rare earth elements are in permanent magnets, phosphors in color television tubes, x-ray tubes, fluorescent lamps, high quality magnets, medical lasers, electronic and computer screens, ipods and energy efficient fluorescent lamps. For all these applications two types of REE products are used:
1. "Mischmetall", a mixture of rare earth oxides and
2. "high purity" compounds containing at least 90% of an individual rare earth element.
In last one decade rare earth elements are also being used in wind turbines, hybrid vehicles, fibre optics.
Large number of metallic and non-metallic deposits have been discovered in state during last 60 years. Both before and after independence the possibility of rare earth elements were indicated in many technical papers. Earlier rare earth mineral mining was reserved for government PSU, the liberalisation in policies has now opened this field for private entrepreneurs. But credit for a clear cut discovery goes to a private mineral mining company viz. M/S Ramgarh Minerals & Mining, based in Bellary Karnataka.
In the year 2012 this company signed an MOU with Rajasthan government to carry out mineral exploration in large area in border district of Barmer. Company vigorously carried its work and first indication was found in 2013, this was followed by drilling and the sub surface rocks gave proof of occurrence of rare earth minerals.
The main discovery is located near village Kamthai, 30kms, South East of Barmer. As per the scientific paper published by company advisor Dr. S.K. Bhushan in 2015, rare earth minerals are associated with carbonatite rock. There is bimodal distribution of rare earth elements. A wide spectrum of calciocarbonatites and associated alkaline rocks are exposed around Kamthai, Rajasthan.
The mineralogical studies exhibit a bimodal distribution of REE minerals. The southeastern block has carbocernaite and the eastern block has bastnaesite (+/-) ancylite/synchysite as the dominant REE minerals followed by parisite and other accessory minerals. Calcite is the most abundant of the gangue phase, followed by biotite, albite, k-feldspar and iron oxide/hydroxide.
Minor and trace gangue phases include pyrite, ilmenite, apatite, siderite, ankerite, amphibole, pyroxene, strontianite, barite, ilmenite/pyrophanite, celestine, clay minerals, sphalerite, pyrochlore, fluorite and Mn-rich phases including hollandite and Mn-Fe oxides. Calciocarbonatite occurring as intrusive veins, sills/dykes and plug, is perhaps a product of crystallization of a primary carbonatite melt generated at upper mantle.
The first phase magmatic calicocarbonatite is alvikite type, rich in carbocernaite whereas second hydrothermal phase, sovite type, is enriched in bastnaesite. The absence of supergene activity and minerals (crandalite, florencite, gorceixite) indicate minor role of secondary enrichment. A rift-related mechanism, thermal equivalent to Deccan flood basalt (65 (+/-) 2 Ma), invoking "Reunion plume - continental hot spot" might have triggered Tertiary alkaline magmatism.
The company has submitted its technical report to Rajasthan government. And is in the process of acquiring mining lease for the explored area. If this project materialises then it would be first mine of rare earth minerals in state. India is not very rich in terms of rare mineral deposits so this discovery has long term implications.
Apart from saving foreign exchange, it would also provide employment to locals, and add to state by way of mineral royalty. Apart from this discovery the only mining processing of such minerals is being carried out along Kerala coast by government of India PSU, Indian Rare Earths Ltd.
It is not out of question to mention that China dominates the mining and trading of rare earth minerals in world. It supplies 95% of all rare minerals consumed by world.
(Source: http://www.merinews.com/)