DETERMINATION OF VARIABLE CUT-OFF GRADE FOR AN OPERATING URANIUM MINE BY GEOEXPLORATION TECHNIQUES: A CASE STUDY OF TURAMDIH URANIUM MINE, SINGHBHUM SHEAR ZONE, EASTERN INDIA
P. K. Adhikari1 , Shalivahan2 , P. Das1 and A. K. Sarangi1
1Uranium Corporation of India Limited, Jaduguda, India
2Department of Applied Geophysics,Indian School of Mines, Dhanbad, India
E-mail: prafullaadhikari@yahoo.com
Abstract
Indian uranium deposits are mostly of low grade compared to many other uranium deposits of the world. Uranium deposits in Singhbhum Shear Zone (SSZ) are vein type and their ore grade distribution and the leaching behaviour along the strike and dip of the ore body is highly heterogeneous due to abrupt change of mineralogy from place to place. Mining of such a heterogeneous ore body with a fixed ore cut-off grade may lead to misclassification of potential economic ore block as waste. The processed product potential of ore is dependent on both the parameters: grade and leach efficiency. Low grade ore with high leach efficiency produces comparable quantity of product as compared to high grade ore with low leach efficiency. Turamdih uranium deposit with six major uranium ore veins located in the west-central part of the SSZ has been developed by Uranium Corporation of India Limited as underground mine. The mine has been developed with a fixed cut-off grade for all six veins. Detailed geoexploration has been carried out underground by radiometric exploration techniques such as channel sampling, bore-hole logging and geochemical techniques such as leaching behaviour study over the configuration of the ore veins. The exploration data has been used to decide an appropriate cut-off grade for different segments of ore veins. This variable cut-off grade has been implemented to enhance the overall economical sustainable recovery of uranium ore, mineral conservation and life of the mine.
Keywords: Singhbhum Shear Zone, Cut-off grade optimization, Integrated geophysics, Turamdih uranium mine, Eastern India.