The Polymetallic Nodules (PMN) Programme is a national programme aimed towards refinement in assessment of nodules in the 75,000 sq. km area retained by India in the Central Indian Ocean Basin (CIOB) and development of technologies for mining and extraction of metals from nodules. India as the first registered “Pioneer Investor” has to undertake different developmental activities for exploring and exploitation of polymetallic nodules towards fulfillment of the obligations relating to development and transfer of technology and training in the use of technology, etc. Ever since India attained this status in 1987, efforts were on survey and exploration, technology development for mining of nodules, extractive metallurgy and EIA studies. This programme consists of four major components viz., Survey and Exploration of nodule in the CIOB; Environmental Impact Assessment Study at the mine site; Development of technologies for mining of nodules and Extraction of metals.
The Survey and Exploration endeavour is aimed at firmly establishing the nodule resource and validating the resource assessed for updating relative concentration and quality characteristics of the Polymetallic Nodules, Survey and Exploration activity was carried out at a close grid in selected marginal blocks. In addition, updating of geo-statistical resource evaluation based on 6.25 km grid sampling in selected blocks has been undertaken and an area of 17,500 sq.km have been outlined in the retained area comprising of consistently high grade abundance for First Generation Mine Site(FGM).
As a part of the ongoing Environmental Impact Assessment study, CTD and Rosette observations near seabed at the test and reference areas were carried out monitoring addition, the box corer samples at the test and reference areas were collected. The monitoring of environmental parameters by collecting samples at the test and reference areas is also carried and appropriate data bases are created.
Deep-sea technology and ocean mining group in the National Institute of Ocean Technology (NIOT) is responsible for the development of technology for mining of polymetallic nodules from the seabed and other underwater components. As a part of technology development for underwater mining, a shallow bed mining system was designed, developed and tested at 451 m water depth successfully for a second time A mining system capable of operating at 6000 m depth with a mining capacity of 25,000 tonne nodules per year was also designed under joint collaborative effort with University of Siegen, Germany. In relation to metallurgy, a semi-continuous demonstration pilot plant to process 500 kg per day of polymetallic nodules to validate the process package developed for extraction of metal values from nodules at Hindustan Zinc Limited (HZL), Udaipur was commissioned in March 2003 and campaigns to validate process routes are continuing. The first process route developed by RRL(B) for extracting the metals has been tested successfully and the activities are progressing to test the process tools of other organisations and to improve the metal extraction. The Department collected about 120 tonnes of nodules from Central Indian Ocean Basin (CIOB), which will be consumed for the metallurgical demonstration campaigns. The data generated during the demonstration campaigns will be used for evaluation and validation of process package already developed. R&D activities for efficiency optimisation for extraction of metals viz. Cu, Ni, Co and Mn were continued. Regional Research Laboratory(RRL), Bhubaneswar and Hindustan Zinc Limited (HZL),Udaipur are pursuing the R&D efforts for optimising the metal recovery/processing steps. National Metallurgical Laboratory, Jamshedpur continued its endeavour for improvement of recovery efficiency for roast reduction ammoniacal leach route in addition to recovery of Manganese as ferro-silico manganese from the waste generated by RRL process route. Another pilot plant is coming up at NML(J) for production of ferro – sillico – manganese. Ore from the residue has been obtained from HZL plant.
A Remotely Operable Vehicle (ROV) has been successfully developed by Central Mechanical Engineering Research Institute, Durgapur (CMERI) as part of the Polymetallic Nodule (PMN) Programme of the Department of Ocean Development (DOD). The ROV is capable of performing underwater survey operations at 200 metres depth and could be operated at a maximum of 2 knots speed. It can carry a maximum payload of 60 kg. The ROV was successfully tested at about 200 m water depth off Chennai coast using the vessel. A. Sideronko during August 2001 jointly by CMERI and NIOT. Design improvements on the umbilical assembly and underwater camera to obtain better picture quality are being made, based on the results obtained from the last sea trials. Development of deep water ROV (ROSUB) is taken up in collaboration with Design and Experimental Design Bureau of Ocean logical Engineering, Moscow. This remotely operated submersible would be capable of operation at a depth of 6000 m.
