Minerals Report - International Seabed Authority

The requirements for sampling to locate mineralisation differ
considerably from the rigorous requirements associated with sampling to
produce mineral resources in the inferred and indicated levels of
confidence, with the latter being a prerequisite for transformation to
mineral reserve (see Figure 6 above). The demands placed upon the
sampling systems also changes considerably depending upon the nature
of the footwall being sampled. For example, hard bedrock and clay
footwalls present radically different problems for sampling tools and
recovery plants to deal with.
Due to the scale of the operations DBM manages for its clients, the
company operates two vessels with sampling capabilities. The Douglas
Bay equipped with a “mega drill” has, and continues to play an important
role in developing offshore mineral resources. However, in order to
overcome some of the challenges presented by the rugged ore body and
footwall conditions that have to be sampled on the Namibian shelf to
confidently deliver indicated resources, the Coral Sea has been equipped
with a large-bore “decadrill” system. Based on direct observation of Coral
Sea sampling holes utilising the Jago submersible, this system has proved
to be capable of sampling very rugged terrain indeed.
Considerable ongoing applied research and development is
focused upon both improving existing sampling tools and designing
completely new sampling systems to further improve the confidence of
results, increase productivity and allow new types of ore body to be
sampled. In addition, a philosophy of continuous improvement is also
followed in terms of the recovery plants aboard the company’s fleet. Very
high levels of security also protect the diamond product, which is not
touched by hand from the moment it is sampled/mined to the time it is
delivered to the client.
Given the long history of involvement De Beers has with the “West
Coast” environment, considerable geostatistical research has been
undertaken. Much of this work is ongoing as geological models; sampling
and mining technologies continue to evolve. In addition, with the
expansion of the mining fleet a lot of research is focused on optimising
mine planning – a very complex area due to the multivariate nature of the
data input required. This is very computationally intensive and
demanding, even for linear programming to resolve.
INTERNATIONAL SEABED AUTHORITY 587