Minerals Report - International Seabed Authority

emote seismic data. He pointed out that with these methods, De Beers is
able to build extremely detailed high-resolution acoustic maps of the
seafloor. He described these maps as containing the kind of information
that is required by mining system designers and people that are involved
with mine planning. Used in modelling, Dr. Corbett said that this type of
information is equally invaluable to decision-makers. Finally, he said that
this type of data gives De Beers a much higher capability in terms of
predicting the distribution of mineralization, a factor that has significant
benefits in terms of resource delivery. Dr. Corbett provided an illustration
of a computer simulation of mineralization distribution in a deposit. The
simulation contained examples of sample holes, the overburden, and the
ore body with coarse clastics and a clay footwall.
With yet another slide, Dr. Corbett showed participants a picture of
the Coral Sea, the first drill ship that De Beers Marine brought into
production in 1991. Dr. Corbett said that the Coral Sea is now equipped
for a 24 hour switchover between evaluation sampling or mining. He also
showed participants the drill system on board the vessel that is used down
on the seafloor for evaluation sampling. He said that the drill system was
specifically designed for De Beers’s purposes and is capable of sampling
very effectively, extremely coarse clastic material down on the seabed. He
described the ore body that was being sampled as very coarse-grained
complex lag gravel that was produced by repeated shore face reworking
during regression and transgression over at least 50 million years.
With regard to processing, Dr. Corbett said that once the ore
containing the diamonds is taken up by the drill system, it is not touched
by human hands during the entire processing operation. He said that the
ore is taken up, passed through a dense media separation plant where the
diamonds are concentrated together with other heavy minerals. He said
that the diamonds are then passed through an X-ray sorting system that
identifies the diamonds specifically. The sorted diamonds are then canned
on a sample-by-sample basis in a specially designed canning machine. Dr.
Corbett said that he final recovery is done under very strict security
because sample integrity is absolutely essential and diamonds are very
small, very valuable. He noted that data analysis and the evaluation of
sampling results is tricky business and has required a lot of very specific
focused research since the mid 70’s.
Dr. Corbett provided participants with an overview of mining
development in terms of deepwater operations. He said that after the start
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