India has the status of "Pioneer Investor" for exploration and exploitation
of polymetallic nodules and has been allotted a site in the Central Indian
Ocean Basin (CIOB) for this purpose by International Seabed Authority (ISBA).
Considerable progress has been made ever since India attained this status in
1987, in the field of survey and exploration, technology development for
mining of nodules, extractive metallurgy and EIA studies. The PMN programme
consists of four components – Survey & Exploration of nodule in the CIOB;
Environmental Impact Assessment Study; Development of technologies for
mining of nodules and Extraction of metals. The programme is guided and
reviewed by the PMN Board of Management.
Survey & Exploration:
Survey & Exploration in the Indian mine site was continued at a close
grid of 5 km for updating relative concentration and quality characteristics of
the polymetallic nodules in different pre-determined blocks. Towards part
fulfillment of the obligations of the Registered Pioneer Investor, action is
underway for the relinquishment of balance 20% of the pioneer area to ISBA.
Environmental Impact Assessment Study:
As a part of Comprehensive Impact Assessment study at CIOB mine
site, a monitoring cruise plan has been finalised which includes study of the
recolonisation activity and extent of restoration.
Technology Development - Mining
NIOT, Chennai has been entrusted with the responsibility of
implementing a major project for development of technology for mining
polymetallic nodules under the PMN programme. In purusance of the
agreement signed between NIOT, Chennai and the Institüt for Konstruktion
(IKS), University of Siegen, Germany an existing crawler at IKS was
refurbished with a manipulator, cutting device, pumping system, electrical,
instrumentation and control systems. The crawler has been designed to
operate on sandy sea bed. It has special track belts with involuted teeth to
compact the bed during operation. Necessary transducers for measurement of
velocity, drum speed, heading and concentration are present with closed loop
controls for speed, heading and slip for crawler locomotion and pumping. A
co-axial cable with an outer steel armour transmits power and signals to the
system and also takes the weight of the vehicle during launching and retrieval
operations. The vehicle has been tested off Goa coast during October 1998
and off Tuticorin during April 1999, March 2000 and September 2000.
During the third test off Tuticorin coast clay bearing mud was
successfully pumped from 410 metres water depth. The fourth test on the
underwater mining system was carried off Tuticorin coast during the third
week of September. During this test successful coordination of crawler
instrumentation and ship instrumentation systems was carried out leading to
the successful completion of maneuverability and pumping tests on the mining
system from 33 m water depth.
As a prt of this project, an in-situ soil tester has been developed and
tested successfully off Tuticorin coast at 34 meters depth, for measuring the
soil properties directly in the ocean floor. As a part of this joint collaborative
programme a design report on underwater mining system for manganese
nodule mining from 6000 m water depth has been prepared jointly by NIOT,
Chennai and IKS, Germany, based on the experience gained during the trial
operations for mining nodules at the rate of 25000 tonnes per annum. The
design reports and future project proposals were reviewed by a Committee at
NIOT during the third week of November,2000. The Project proposals were for
carrying out in-situ measurements of soil at the Central Indian Ocean Basin,
for qualifying collector and crusher systems at 300-500 m water depth and for
development and qualification of the Integrated Manganese Nodule Mining
System. The Committee has suggested certain modifications for incorporation
in the design report, which are being looked into.
Unmanned Submersible:
A proposal for developing an unmanned submersible capable of
operating up to 6000 m depth has been approved. National Institute of Ocean
Technology (NIOT), Chennai has been identified as the nodal agency to
implement this project.
Technology Development – Metallurgy:
Establishment of 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 is progressing at
Hindustan Zinc Limited (HZL), Udaipur. It is expected to be commissioned in
May 2001. The Department collected 45 tonnes of nodules for this
demonstration plant with the help of research vessel R.V.A.A Sidorenko in
addition to 80 tonnes already collected for this purpose. The demonstration
campaigns will generate data for evaluation and validation of process package
already developed.
R&D efforts were continued to optimise the process steps being pursued
at RRL (B) and HZL (U). A project for the recovery of Ferro-Manganese alloy
from the waste generated by RRL process route is continuing at NML (J).
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