Mining in focus
The biggest mining ship, MV Peace in Africa was launched in 2007 for the exploration of
the SASA (South African Sea Areas) by the conglomerate De Beers. The most important
and unique feature of the mining ship is that it is the first vessel to carry out marine
mining in the western seacoast part of South Africa, in the Atlantic Ocean.
Steenkamp
Heavy mineral placer deposits extend
onto the continental shelf, where it can
be mined.
materials in shallow waters. The rotating
cutterhead is usually an open basket
with hardened teeth or cutting edges
the suction pipe is normally located
within the basket. In standard operating
conditions the dredge is swung back
and forth in an arc pivoted from a large
post or spud attached to the stern.
Extreme mining
Marine miners face extreme working
conditions with operations typically
running for about 300 calendar days a
year, excluding days for maintenance or
unfavourable sea conditions. Operators
also must work in temperatures
of around 1ºC, pressures of about
300 to 500 bars, several kilometres
from shore, cross-cutting currents
and uneven topography. To navigate
heterogeneous mineral distribution,
companies will first need to develop
self- propelled mining devices that
could detect promising targets and
screen the ore at seabed level, instead
of pumping it up to the surface. These
types of technological developments
optimise power consumption and
have cost and time saving benefits.
Environmental concerns
Seafloor mining presents significant
threat to the marine environment.
In South Africa, only 0.4% of the
EEZ is officially protected. One of
the biggest concerns is that marine
organisms on the seafloor would not
survive, owing to the generation of
a continuous sediment plume.
In addition, the disturbed continental
sediments cause a change in the chemical
characteristics of the water column,
due to the release of potentially toxic
elements, such as radioactive materials,
methane, hydrogen sulphide and heavy
metals locked in the sediments. In
addition, the release of heavy metals
from seabed sediments could also
l