The national programme on Polymetallic Nodules (PMN) consists of three components: survey & exploration of polymetallic nodules in the Central Indian Ocean Basin ( CIOB) including Environmental Impact Assessment Study (EIA), development of technologies for mining of nodules and extraction of metals. The programme is guided and reviewed by the PMN Board of Management.


3.1 Survey & Exploration

Survey & Exploration in the Central Indian Ocean Basin (CIOB) mine site was continued for revalidation of relative concentration and quality characteristic of nodules in different pre-determined blocks. The sampling at a grid interval of 12.5 km in the pioneer area has been completed. The data base has been updated on the basis of latest survey. As required by the International Sea-Bed Authority, the report recommending 10% additional relinquishment of the pioneer area to the International Seabed Authority has been prepared & finalised on the basis of up- dated bathymetric and sampling data.


3.2 Environmental Impact Assessment Study

Baseline time series oceanographic data was continued to be collected in the CIOB using three deep seabed mooring systems. An Indian delegation visited Gelendzhik, Russia to formulate and finalise baseline data collection activity which has been commissioned with the help of Chartered Vessel MV.A.A. Sidorenko. This activity is undertaken with the assistance of the Russian Institute Central Marine Geological & Geophysical Expedition (CGGE) under an MOU signed between Russian Federation Committee on Geology and use of Mineral Resources, Government of Russian Federation and Department of Ocean Development. As a part of EIA Programme the benthic disturbance activity has been formulated with the participation of National Institute of Oceanography, Goa and CGGE Russia. This activity will be initiated in March/April 1997 with a chartered vessel fitted with special disturber.


3.3 Technology Development- Mining

The updated Remotely Operated Vehicle (ROV) capable for operation upto 250 metre water depth with 5 degree of freedom is fabricated, assembled and checked out for field trial at Idukki lake, Kerala. A manipulator has also been designed and fabricated for integration with ROV for performance evaluation. Also a remotely operated crawler to mine heavy minerals from sea-bed upto 250 metre with a capacity of 100 ton per hour is designed. Design and development of multi-user system for deep sea application are in progress.

A long range programme profile for development of integrated mining system for exploitation of polymetallic nodules from Central Indian Ocean Bay is formulated. As a first phase, finalisation of an action plan for a joint development programme with University of Siegen, Germany and National Institute of Ocean Technology (NIOT) Madras is under process, according to this existing crawler at the University of Siegen will be modified and tested jointly in Indian waters.


3.4 Technology Development -Extractive Metallurgy

Pilot plant campaigns for both roast reduction-ammonical leaching route and sulphur dioxide-ammonical leach route along with supportive experiments in the leaching and solvent extraction are completed at the National Metallurgical Laboratory, Jamshedpur NML(J) and Regional Research Laboratory, Bhubaneswar (RRL-B) for evaluating the process technology status and planning the activities in the 9th Plan period.

Acid leach -pressure leach route laboratory scale experiments were carried out with 5 litre autoclave at Hindustan Zinc Limited, Udaipur HZL(U). Cobalt cake and Cobalt-nickle sulphide solution generated at NML and RRL respectively are sent to Bhabha Atomic Research Centre, Bombay for extraction of metals as a part of downstream activity.

For establishing the techno-economic feasibility of a commercial plant, process data from a continuously operating plant is necessary. For this an action plan to establish a pilot plant with a capacity to process 500 kg nodules per day is initiated.