Ongoing exploration activities by Hindustan Zinc Ltd (HZL) have yielded significant success with an increase of 28.7 Mt to its reserves and resources, prior to a depletion of 5.8 Mt in FY 2008. Contained zinc-lead metal has increased by 4 Mt, prior to a depletion of 0.6 Mt during the same period. Total reserves and resources at 31 March 2008 were 232.3 Mt containing 27.5 Mt of zinc-lead metal. The reserves and resources position has been independently reviewed and certified as per JORC standard.
The success of exploration has primarily been in the Sindesar Khurd and Rampura Agucha mines. The sustained exploration and aggressive drilling programme at Sindesar Khurd mine has successfully augmented the resource base to the current level of 37 Mt, making it the second largest orebody in HZL’s portfolio after Rampura Agucha, with potential for further additions, through ongoing exploration. In FY 2008, the drilling program successfully increased the strike length, by 300 m, to 1,600 m averaging 5.8% Zn, 3.8% Pb and 215 ppm Ag.
At Rampura Agucha, 28,000 m of drilling in 32 holes were carried out to outline mineralisation below a depth of 550 m. Of these, 29 holes intersected ore widths with significant grades averaging 15.5% Zn and 2% Pb. The combined reserves and resources at Rampura Agucha alone have been augmented to 107.3 Mt at end March 2008, achieving the landmark of crossing 100 Mt in reserves and resources.
The group’s exploration philosophy has been to replace every tonne of ore mined with at least one tonne of resource. HZL has dynamically increased its exploration focus, through a team of 40 geologists employing the latest geophysical, geochemical and GIS technologies and high speed deep drilling equipment. This has resulted in an addition of 110.7 Mt of reserves and resources, before depletion of 22.1 Mt, in the period from April 2003 to March 2008.
HZL is India’s only integrated producer of zinc and lead and among the world’s leading integrated producers. Its metal production capacity is nearly 670,000 t/y with its smelter operations situated in Chanderiya, Debari and Visakhapatnam. HZL has zinc-lead mines in Dariba, Rampura Agucha, Sindesar Khurd and Zawar. The company is a subsidiary of the NYSE listed, Sterlite Industries and London listed diversified metals and mining major, Vedanta Resources.