Rare Metals include Niobium (Nb), Tantalum (Ta), Lithium (Li), Berylium (Be), Cesium (Cs) etc. and Rare Earths include Lanthanum (La) to Lutecium (Lu) and Yttrium (Y). These metals are strategic in nature with wide application in the nuclear and other high tech industries such as electronics, telecommunication, information technology, space, defence etc. RMRE group of AMD has been carrying out investigations for the last five decades in favourable geological environments to establish the resource base of these metals. Important minerals of these metals are beryl (Be), lepidolite (Li), spodumene (Li), amblygonite (Li), columbite-tantalite (Nb-Ta), pyrochlore (Nb) and xenotime (Y and REE).

Occurrence

The minerals beryl, columbite-tantalite, lepidolite, spodumene, amblygonite etc. generally occur in the pegmatite belts in different states of India viz. Rajasthan, Bihar, Andhra Pradesh, Karnataka, Orissa, Madhya Pradesh and Tamil Nadu. Pyrochlore occurs in carbonatite complexes whereas Xenotime occurs in the riverine placers in Central India.

The metal content of such indian minerals are as follows:          

Click here to see the Important localities of RMRE occurrences located by AMD

Recovery Operations

Small scale recovery operations (3 - 5 tonnes per annum) are carried out by AMD to recover columbite-tantalite mineral from pegmatite gravels. Columbite-tantalite is heavy  (sp. gravity 5.3 - 7.8 ) and therefore gravity separation is being used to separate it from the other pegmatitic minerals  such as quartz and feldspar which are light (sp. gravity 2.8). Several recovery plants were set-up in Bihar Mica Belt and Bastar-Malkhangiri Pegmatite Belt for the recovery of  columbite-tantalite. In addition, at Marlagalla, Mundur and Arehalli in Karnataka, recovery plants were set-up for the recovery of columbite-tantalite with spodumene as co-product. Beryl, which occurs in these pegmatites is generally hand sorted and recovered, based on colour, lustre and hexagonal crystalline form.    

At present these operations are being carried out in Bastar district, Chhattisgarh and Jharsuguda district, Orissa.

Xenotime, the Y and REE bearing phosphate mineral,  is associated with riverine placers in  Siri River and Deo River in Madhya Pradesh and Jharkhand respectively.  Xenotime is a heavy mineral (Sp. gravity 4.5) associated with sands (quartz and feldspar) in the rivers traversing Chhotanagpur Gneissic Complex.  The other heavy minerals include monazite, zircon, ilmenite, magnetite, garnet etc. along with some amount of columbite.

Presently xenotime is not being investigated and the material recovered from earlier operations has been stockpiled in departmental godowns.

Purchase of Rare Metal Minerals

The Atomic Minerals Directorate purchases tantalum, niobium and beryllium ores as well as Nb-Ta bearing residues, generated by tin plants, analysing > 50% (Nb+Ta)₂O₅ at the prices fixed vide notification No.9/1/92-AMD(R&D) dated 06.12.1993.

Sale  of  Lepidolite

A limited stock of lepidolite (lithium mineral) available with AMD is earmarked for sale as per the terms and conditions stipulated in the DAE  notification No.9/1/92-AMD(R&D) dated 06.12.1993.