14 
Offshore Exploration of Ores 
Navigation Oceanographic Survey of Localization 
(or Survey Ore Depoalts of launched © 
©) eatetmen @ wncerwster mesourng chain © deep arving probe wan Survey Gauges 
Eraaa coon) swt) wooatzabes buoy wv 298 carmen and bgt —— 
ed Soe @ mesa = ® 
(irensponder/redan core for samcting sediment wh Ney / 
Bathymetry < so er jeans A / 
rerow beam sounder (BS) © batrysonde (erode) DUR namping of nocses / / 
L ocaiteadal COMIN messuremert Of ro 
nove 20m recorders ote / a 
Reflection pen / 
Figure 7.—Offshore exploration of nodules. 
_ Source: United Nations, Economic implications of sea-bed mineral development in the 
international area: report of the Secretary-General, A/CONF.62/25, May 22, 1974, p. 13. 
Major changes in the metals market will affect. the selection of a 
mine site, either making lower grade nodules profitable or confining 
mining operations to only the highest grade deposits. The type of 
metals recovery process used or the metals market the company desires 
to enter will feed back into site selection. For example, a company may 
wish to market cobalt, copper, nickel, and manganese while another 
company may be interested in extracting and marketing only cobalt, 
copper, and nickel. These considerations will affect the size of the 
mining operation necessary, desired metal values of the nodules, and, 
hence, the site selection. 
The efficiency of the mining system will also play a role in determin- 
ing the minimum size economically feasible as a mining site. As yet 
there are no hard data on recovery efficiency. The total amount of ore 
mined from workable or accessible areas of a mine site depends on the 
pick-up efficiency of the collecting device and the mine sweeping effi- 
ciency or ratio of area actually swept by the bottom device to the area 
accessible for mining. Limited experience indicates that the dredge 
head pick-up efficiency is somewhere between 30 percent and 70 percent, 
