The metallic minerals of the Pacific Seafloor

The metallic minerals existing on the seafloor of the Pacific Ocean display a great range of variations in their chemical and physical properties. These deposits are considered as an important source of raw material because of their contents of Ni, Cu, Co, and Mn. The two dominant types of deposits are ferromanganese encrustations and nodules. The nodules, being more important with regard to an economic use, are concentrated at great depth of water where the rate of sedimentation is rather low. They accumulate very slowly around nuclei material. The occurrence of nodules and crusts has been established very well in the Pacific Ocean as the best mining sites can be assumed there. The data of exploration show that the most encouraging situation is given in a broad east-west belt situated in the equatorial North Pacific. The conditions forming nodule deposits rich in Ni and Cu and with high nodule coverage are more favourable in this part of the Pacific than in other regions. The different factors controlling the distribution of nodules are considered. The content of metals, its regional variations and trends from the different parts of the Pacific Ocean are discussed. Distinct types of nodules reflect different sources of metals and different environments of growth. Only a small part of the Pacific nodule deposits can be mined because of technical and economical reasons in today's sight. A basic model to encounter nodule occurrences of economical importance and a rough empirical formula to calculate the extension of a potential license area are presented and discussed. The Economic Zones share about 40% of the total size of the Pacific but contain likely only less than 10 % of the economically interesting nodule deposits. As a start of the deep-sea mining technically seems to be possible at the end of the eighties an economical production is able to begin early in the nineties. The annual output of a single mining enterprise and the possible contribution of nodule mining to the world market until 2000 (5 mining enterprises) and 2025 (20 mining enterprises) are regarded. A comparison with the continental resources of metal show that the nodule mining can support only the traditional metal production but not replace in today's sight. The investments of capital required for deep-sea mining are very high. If the UN Conference on the Law of the Sea may lead to unrealistic results being detrimental for further activities, the development of deep-sea mining might to be paralyzed. The technical systems of exploration and mining have to take into account the particular properties of the marine environment. The technical requisites have been developed and successfully tested already. Two different metallurgical processes seem to be economically suitable. 8 consortia or groups at least are known to be engaged in the field of nodule mining.