Extraction processes for recovery of metals from seabed nodules have been developed at the National Metallurgical Laboratory, Jamshedpur, Regional Research Laboratory, Bhubaneswar and Hindustan Zinc Limited, Udaipur. Of the 15 process routes investigated initially, five potential routes were shortlisted for further development on a laboratory scale and further three process routes for upscaling. These are:

Roast reduction ammoniacal leach at National Metallurgical Laboratory, Jamshedpur .

Ammonia SO2 leach at Regional Research Laboratory, Bhubaneswar .

Acid leach-pressure leach at Hindustan Zinc Limited, Udaipur .

Evaluation of test results and monitoring of the R&D activities are being carried out by Engineers India Limited, New Delhi. Investigations along the above process routes are now at an advanced stage. Two pilot plants, each of about 250 kg nodules processing capacity ,per day are in the final stages of erection at National Metallurgical Laboratory and Regiona1 Research Laboratory, Bhuvaneswar. These plants are expected to be commissioned during 1992.

The end of the R&D phase will be marked by a feasibility report for the semi-industrial phase based on which the detailed engineering, procurement, installation and commissioning of the test mining system will be undertaken during the coming years .

The activity profile of the programme during the next phase includes spot bottom sampling using free fall grabs, dredging and collection of bulk samples, completion of multi beam swath bathymetric maps using hydrosweep system, continuation of sea floor mapping of the seabed nodules covering sediment distribution, continuance of sea floor mapping of the seabed for its micro , topography and local structures, geotechnical studies of nodules as well as associated sediments and oceanographic data collection. Evaluation of pilot plant performance and design of semi-industrial plant and testing of collector, experimental studies on lifting systems, testing of integrated systems in shallow basins and evaluation of performance are envisaged. These programmes are being periodically monitored at different levels by competent group of experts. The Ocean Science & Technology Board and a Steering Group constituted by the Council of Scientific and Industrial Research periodically monitor and review the progress of the programme. In addition, Engineers India Limited has been entrusted with the task of monitoring and evaluation the progress of work from time to time.