Mining in focus
Introducing
nanotechnology
to mining
The micro-nanochip technology is called the lateral gate with
interdigitated drain-source field-effect transistor (LAGIDDS-FET).
Any word that contains the word ‘nano’ implies something extremely small;
so small that it cannot be seen with the naked eye. Nanotechnology is no
different. Ironically, this technology that relies on the smallest particles can be
used in a typical mining environment, writes Dineo Phoshoko.
T
owards the end of 2018,
the Department of Science
and Technology (DST), the
Nanotechnology Innovation
Centre (NIC) at Mintek, and the Council for
Scientific and Industrial Research (CSIR),
hosted a joint 10th anniversary workshop
at the CSIR Convention Centre, Pretoria.
The workshop commemorated 10 years of
excellence in nanotechnology research in
South Africa.
What is nanotechnology?
The National Nanotechnology Initiative
describes nanotechnology and nanoscience as
the study and application of very small things
that can be used in different scientific fields
such as chemistry, physics, material science,
and engineering. Dr Lucky Sikhwivhilu,
head of the DST Mintek NIC, explains
nanotechnology as technology that is based
on the smallest entities that are used in its
development. “We’ve all come to know that
every technology depends on the quality of
material, regardless of what these materials
are,” explains Sikhwivhilu.
Nanotechnology often looks at how material
can be made at nanoscale, and in turn, use
the materials — with enhanced properties
[30] MINING MIRROR APRIL 2019
— to build technologies that would be more
efficient, powerful, sensitive, reliable, and
more. In simpler terms, nanotechnology is an
application of the science of the nanoscale —
this according to Dr Bonex Mwakikunga, a
chief research scientist on nanoscale physics
from the NIC National Centre for Nano-
Structured Materials at the CSIR. Nanoscale
can be calculated by dividing one metre by one
billion; the answer would be one nanometre.
Applications of nanotechnology
Nanotechnology is applicable across different
areas such as medicine, agriculture, and energy.
Mining is another area where nanotechnology
can be applied. Speaking to Mining Mirror
during an interview, Sikhwivhilu outlined
three main applications of nanotechnology in
the mining industry.
Rapid diagnostic tests (RDTs)
Mintek has become the first (and only)
organisation in South Africa to develop RDTs.
RDTs are self-help tests that detect an HIV
infection in one’s bloodstream. South Africa
ranks among the highest countries in the world
with HIV infections. According to Statistics
South Africa, the total number of people living
with HIV in the country increased from 4.25
million to 7.52 million between 2002 and
2018. Sikhwivhilu highlights that the tests are
not specifically created for miners only, as they
can be used for anybody who needs it.
The tests have been developed using
nanogold particles. “The development is really
based on materials such as nanogold, or in
other words, gold at nano scale,” Sikhwivhilu
explains. Gold is an interesting chemical
because it is usually associated with a dark
yellow colour; however, he points out that at
nanoscale, gold can exhibit a different colour,
generally red. Gold’s interaction with light
changes, depending on its size. “In our case, we
are looking at gold as a particle; we are looking
at gold as a rod. We look at gold even as a wire.
We can fabricate that and there are various
techniques for us to do that,” Sikhwivhilu says.
With regard to RDTs, a particle’s surface
will be decorated with biological molecules or
other chemical molecules to give it the desired
potency. From a diagnosis point of view, a
receptor can be inserted which interacts with
whatever is being examined in the human
body. “In the case of HIV for example, you
may be looking for antibodies.
“So, you insert something that has a very
good relationship with antibodies, so when
they come together, it’s almost like a lock and
a key. They come together, and they lock each
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