Mine excursion
Bureau Veritas’ Centurion laboratory
specialises in testing coking coal.
in Zimbabwe, which tests negative
for most coking coal properties, but
exports extremely high-quality coke.
According to Marc Roussel, senior
vice-president Africa Commodities and
Industry & Infrastructure Division at
Bureau Veritas, Africa is a big market
for the company. “West Africa is
currently one of our main focus areas,
and we have a significant presence
here,” says Roussel. He questions
the fact that many companies doing
exploration work in Africa still send
their core samples to countries like
Australia or Canada, while there
are world-class facilities in Africa,
especially in South Africa. “It will cut
costs significantly in the initial stages of
a project if the cores are analysed locally,
or at least on the continent,” he says.
Generating the data
“Geologists from across Africa send
in their samples, and we assist the
exploration companies with their flow
[16] MINING MIRROR MARCH 2018
diagrams and with whatever they want
to analyse for,” says Carstens. Carstens
goes on to explain that it is important
for an exploration company to test
the quality of coal to understand the
deposit better, which will also help if
a junior has to raise money or when
they need financial assistance. “The
more properties a company tests for,
the more products it can expose to
the market,” says Carstens. He points
out that the lab only generates data
and based on these models, assist
with the mine planning. “We only
supply the numbers for them to do
the work; we do not get involved with
mapping and making recommendations.
That is why the quality and the
reliability of the numbers are of
utmost importance,” he adds.
The lab receives many different
cores and each core requires different
analyses. A large diameter (LD) core,
for example, may require drop-shatter
analysis. A drop-shatter test estimates
the capacity of coal to resist breakage
during handling and transportation.
Accurate, independent drop-shatter
analyses provide a true value for coal.
It is supposed to simulate how the coal
will break during actual mining. After
the drop-shatter test, they then do
wet tumbling, which simulates the wet
breakage of coal in the washing plant.
“This data is important for especially
the plant designers,” says Carstens.
Floating the core
After the samples have been received
in the laboratory, the first stage is
crushing the coal, or drop shattering
it, as explained above. For the
drop-shatter test, it is better to use
LD samples. Although LD core is
the most preferred, it is also the most
expensive. “We also use bulk samples,
where a piece of the ore body is
opened up and basically mined, so it
is really a mini open pit. This sample
is then shipped to us,” says Carstens.