Emerging trend of uranium mining: The Indian scenario

In the Singhbhum Thrust Belt of Jharkhnad, a low-grade large tonnage deposit at Banduhurang is being planned for exploitation soon. After the initial evaluation and computerised orebody modeling, open-pit mining method has been considered as the most favourable option. Uranium orebody explored at Lambapur-Peddagattu in Andhra Pradesh have been planned for development by both open cast and underground mining methods. A large sandstone hosted uranium deposit at Domiasiat, spread over two distinct blocks has been found within a depth of about 45m. Pre-mining activities are also set to begin in a few more deposits where the exploration is in advance stage and some reserves have already been identified. A large uranium reserve has already been established within the carbonate host rock at Tummalapalle in Andhra Pradesh. New mining technologies are emerging where all the strenuous mining activities are automated. Development of cutting technology in place of conventional drilling and blasting, use of electronic detonators, environment friendly explosives etc are some the areas of future development. New mines have been planned with deployment of energy efficient electro-hydraulic equipment. The only uranium ore processing plant of the country at Jaduguda, in operation since 1968 is based on acid leaching technology. The final product of this plant is magnesium diuranate or yellow cake. Jaduguda plant has been expanded twice to treat the ore of Bhatin and Narwapahar mines. In the coming years, ore of Bagjata mine will also be fed to this plant. A new plant at Turamdih is being set-up to treat the ore planned to be produced from Turamdih and Banduhurang mines. The flowsheet of this plant is similar to that of Jaduguda. Another new plant at Seripalli has been planned in Andhra Pradesh to treat the ore of Lambapur-Peddagattu mine. A plant near the mine site at Domiasiat in Meghalya will be constructed with some modified process technology because of different ore characteristics. Followed by conventional grinding, the thickened slurry of sandstone will undergo two stages of leaching - weak acid (WAL) and strong acid (SAL). Resulting filtrate will be clarified, concentrated in ion exchange and precipitated along with magnesia as magnesium diuranate. A plant based on alkali-leaching technology is being proposed at Tummalapalle to treat the carbonate bearing host rock. Resolving the process know-how for alkaline leaching of Tummalapalle ore is now the emerging area for research and development. The uranium ore in India are generally of low grade, which necessitates production and processing of large quantity of ore. This results in generation of large volume of solid waste and effluent. The operating underground uranium mines of the area are carefully designed with suitable stoping method (cut-and-fill) to accommodate maximum tailings generated during the ore processing. As the mining work progresses, the void created are sequentially backfilled utilizing about 50% of the deslimed neutralized tailings. Only the finer fraction of the neutralized tailings is stored in tailings pond separating it from the public domain. The only tailings pond of the country at Jaduguda with natural high hills on three sides and a very sound impoundment arrangement, has been progressively expanded to accommodate the tailings generated from Jaduguda plant. Tailings management at new sites: New underground mines in Singhbhum will have provisions of backfilling utilizing coarser fraction of tailings. The tailings pond proposed at Turamdih will be designed in line with Jaduguda tailings pond. The tailings pond at Seripalli is being envisaged with thickened tailings disposal system. The proposed open cast mine at Domiasiat is being designed to sequentially store uranium tailings as backfill material after artificial lining at the pit bottom. The finer fraction of the tailings will be impounded in the tailings pond to be constructed adjacent to the plant. The new tailings ponds are being envisaged with sound impermeable artificial liner at the floor to pr event any downward movement of effluent. Various laboratory studies are being conducted to implement thickened tailings disposal (TTD) system at Seripalli. Self-reliance in basic raw materials being the dominant paradigm of nuclear power programme, the growth of uranium industry in the country is expected to grow matching with the phenomenal growth of nuclear power generation. Apart from supplying the raw material for nuclear fuel, the industry will greatly contribute towards development of infrastructure, mining technology and generate employment opportunity in the nation