New Scenarios Of The World Metal Markets And He Eventual Contribution From Deep Sea Mining
Authors: Lenoble J-P 
Published: October 2008

In previously centrally planned economy countries, several deposits present characteristics that would not allow them to be classified as mineral in market economy countries. Thepresent production cost does not consider the actual value of energy, transportation and labour. Also the pressure of environmental concerns will imply new capital costs to improve the processing facilities. The political changes will progressively restore the actual costs. Consequently, some operations must close, others will have to reduce their production by concentrating on higher grade ore. On the consumption side, the decreased demand from the military, which presently allows exports to the West, will be replaced by an increased demand from industrial sectors such as transportation and consumer products. In South Africa, the abandon of the apartheid policy will progressively involve the reappraisal of labour costs. Some operations will experience difficulties to maintain their activity. The global balance of demand-supply could change and the need for new sources of commodities could appear earlier than previously forecast. Economic feasibility studies demonstrated that polymetallic nodules have the same value than land-based low-grade nickel laterites and manganese deposits that are considered as the next-to-be-developed resources. However the technical risks inherent to deep sea operations require presently a higher ratio of return. This gap could be reduced if research programs are maintained that would ensure better reliability of the different components of deep sea equipment. It will enable future investors to choose between political risks in developing land-based resources and reduced technological risks in deep sea mining.

DEEP-SEA AND LAND-BASED DEPOSITS

Deep sea polymetallic nodules were discovered in 1873. During the seventies, more than one billion of our present dollars has been spent on exploration of the ore deposits and on studies of the mining and processing technologies. More than fifty companies, registered in eight different countries, have invested in such investigations. The main expectation of this important outlay was the quality of the ore. As shown in table 1, polymetallic nodules contain manganese, nickel, copper and cobalt in amount comparable to other land-based deposits that were mined at this period.

Table 1- Metal content in weight percent of the nodules and of low-grade land-based deposits mined during the seventies.(Available in full paper)

However no land-based deposit contains those four metal together. Nickel laterites, than can be divided in poorer limonitic ore (1 to 1.5% Ni) and richer silicate ore (garnierite, 1.5 to 2.5% Ni), are generally holding cobalt (10 times less), but no copper or manganese. In nickel bearing sulfide deposits, nickel is generally associated with copper; they are richer in both metals (1.7 to 8% Ni, 1.5 to 7% Cu);they also can retain cobalt (2 to 15 times less). The copper mines in Zaire and Zambia (African Copper belt) produce cobalt; those two countries account for 80% of the Western world recoverable reserves; the cobalt content (0.12 to 0.94%) is 6 to 12 times less than the copper one (2.5 to 6%).