in specific localities for tonnage, grade, and opera- 
tional costs. 
In support of the NOAA DOMES Program, the 
U.S. Geological Survey is continuing basic scientific 
studies on details of nodule characteristics, sedi- 
ments, sedimentary water, plume dispersions, and 
settling rates and associated geologic investigations. 
State of Technological Development 
The state of technology in the developing deep- 
seabed mining industry is quite well advanced. Pros- 
pecting and exploration activities have been carried 
out by a number of companies since the early 1960s. 
The basic methods of exploration have advanced 
from random tracking and sampling with wire line 
buckets and drop corers or grabs to well designed 
exploration using precision depth recorders, deep 
towed instrument platforms with subbottom profilers, 
side scan sonar, T.V., stereo-color photography, and 
free fall boomerang box corers and grabs. Real-time 
data reduction using computers is becoming standard 
procedure. Bulk sampling for metallurgical purposes 
has continued to rely on primitive, but adequate, 
bucket dredges. Major gaps in exploration technol- 
ogy are found in the very slow rate of exploration 
coverage (2 to 3 knots with towed platforms) and 
in the testing of large areas of engineering properties, 
a slow and unreliable process with results that are 
difficult to confirm. Navigational and positioning 
capabilities are fully in line with the accuracies 
needed for exploration and, probably, for commer- 
cial production needs. 
The mining process involves gathering the nodules 
from the seabed in depths up to 6,000 meters and 
lifting them to a surface platform. Two basic meth- 
ods for coiiection and lift have been tested at sea. 
One is a continuous bucket line which involves an 
endless rope looped to surface platforms and ro- 
tating slowly so that buckets attached to the line 
will drag across the bottom at predetermined inter- 
vals as the platforms move across the nodule field. 
All the mechanical problems for this system, which 
involves some 9 kilometers of line and hundreds of 
buckets, have yet to be resolved fully, and it may 
take several years to perfect the system. Unverified 
cost advantages are claimed for the bucket line over 
the hydraulic system, which has also undergone at- 
sea tests using a gathering device which is towed at 
the end of the hydraulic pipe. Pump suction or air 
lift methods have both been tested, but not at full 
scale. Four major consortia now plan tests under 
actual mining conditions, though at less than pro- 
duction capacity. One of these will introduce a con- 
trolled gathering device which will traverse ‘the bot- 
tom under its own power instead of under tow by 
the surface platform. The testing and evaluation of 
these systems may take 2 to 3 years. At that time, 
investment decisions for full-scale commercial pro- 
duction systems would be made. 
Major shortcomings in the technology of deep- 
seabed mining can only be resolved by actual opera- 
tion. They include the ability to match the seabed 
equipment to the physical characteristics of the 
seabed and the ability to forecast environmental dis- 
turbances caused by the operations. It is likely that 
any major technical problems would involve equip- 
ment reliability under the stress of continuous opera- 
tion. Transportation and unloading requirements 
should present few technological surprises, and 
standard procedures can be adapted to these tasks. 
The technology of processing the ore to extract 
the metals has been well developed. Public state- 
ments by U.S.-connected companies and develop- 
ment work by the U.S. Bureau of Mines indicate 
that there are several potentially economic options 
in this regard. Unquestionably, improvements in 
processing technology will be sought as full-scale 
plants come on stream, but it does not seem at this 
time that there are any major technological deficien- 
cies to be overcome. 
In summary, the technological development of 
ocean mining systems is well advanced for first 
generation systems, although the reliability of ma- 
terials and design has yet to be tested under con- 
tinuous operational stress. The next 2 to 3 years 
should be significant in the confirmation or rejection 
of the present, partially developed, concepts. 
Potential and Importance to the United States 
Importance of the Minerals 
The four metals of principal interest contained in 
manganese nodules are copper, cobalt, manganese, 
and nickel. Of these four metals, the United States 
imports about 98 to 99 percent of annual cobalt 
and manganese consumption, over 70 percent of 
nickel consumption in an average year, and 25 per- 
cent or less of annual copper production. Table 6—1 
compares annual consumption, mine output, reserves, 
Table 6—1.—Statistics for value metals obtainable 
from manganese nodules’ 
In thousands of short tons. 
Annual 
consumption Annual 
(primary and mine 
Reserves as 
years of 
secondary) output Reserves consumption 
Copper 2,350.0 1,610 93,000 39.6 
Cobalt 10.3 0 0 0 
Manganese 1,307.0 0 0 0 
Nickel 227.6 17 200 0.9 
DS EE a 
1U.S. Department of the Interior, Bureau of Mines. Com- 
modity Data Summaries—1977. pp. 42, 46-7, 98, 112-13. 
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