ABSTRACT:

India is currently establishing a 500 kg/d processing plant to treat ocean nodules. The plant is mainly based on the process developed by Regional Research Laboratory, Bhubaneswar, and Bhabha Atomic Research Centre, Mumbai. It envisages reducing nodule in aqueous NH3 -SO2 solution, followed by solvent extraction of copper, pre-concentration of Ni and Co as sulphide, dissolution of mixed Ni and Co sulphides, and finally solvent extraction of Co to produce both Ni and Co as metals. While the plant is being erected, the research activities are continuing to im prove process parameters, and to establish the use of secondary and by-products generated by the process. This paper highlights the process being tested, problem areas requiring special attention, and activities to develop technologies to treat the waste and by-products.

INTRODUCTION

On 26th January 1981,- the Republic Day of India- Indian Research vessel "Gaveshani" collected the first sample of polymetallic nodule from Indian Ocean. Since that day, India has carried out a large programme involving survey, exploration, mining, geology, and metallurgy of such nodules. About half a dozen institutes, and engineering companies in India are involved in research and development activities related to nodules. The Indian government generously supports these activities through Department of Ocean Development, Council of Scientific and Industrial Research, Department of Atomic Energy, and Ministry of Mines (Muthunayagam,1999). As a result of these efforts, India is recognized as a "pioneer investor", and it is at the verge of testing a metallurgical process in 500 kg/day semi continuous plant. For the past two decades, several Indian organizations namely; Regional Research Laboratory (RRL), Bhubaneswar; National Metallurgical Laboratory (NML), Jamshedpur; Hindustan Zinc Ltd (HZL), Udaipur; Bhabha Atomic Research Centre (BARC), Mumbai; and Hindustan Copper Ltd. (HCL), Ghatsila have explored different methods of recovering metal values from polymetallic nodule.

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