MINING IN FOCUS
Mechanisation not new
Mechanisation is not a brand-new idea. South African underground
mines have been grappling with its implementation since the early 80s,
and they are still not close to an acceptable solution. Great strides have
been made, nevertheless, and there are several examples that can serve
as case studies for making mining in deep underground environments
safer and improving efficiencies and productivity by introducing
mechanised methods.
Consulting engineer Roger Dixon has spent more than 47 years in the South
African mining industry, many of those on projects aimed at introducing
mechanised methods. Dixon was one of the guest speakers at the recent
African Mining Network, of which African Mining is one of the sponsors.
Dixon says a mine needs a clear vision and strategy to successfully introduce
mechanised mining into platinum or gold mines in South Africa.
“In 1994, when I worked at Anglovaal, we had a long-term vision and asked
ourselves where we would get an individual rock drill operator from in
20 years,” says Dixon. At that stage, he adds, the average
age of all rock drill operators in South African mines
was older than 40. “No matter what we did, using
non-mechanised methods was not going to be
sustainable, so we introduced mechanised
equipment, mostly on the Elsburg Reefs in
the Witwatersrand Basin.”
“More importantly, you have to pick the right team. The greatest soccer
teams in the world appoint the best managers, who in turn buy the best
players to suit their game plan. And in most cases, they never use old
players. It should be the same in a mining operation.”
Dixon emphasises the need to be adaptable to change. “If the geology
becomes complex, for example, you have to be willing and able to change
the original design. If there is too much dilution, the design needs to
change, bearing in mind that these machines are large and they don’t like
inclinations above nine degrees.
“For the Target project we redesigned the infrastructure at Anglovaal’s
Loraine mine in the Free State because the mine initially had a vertical shaft
and a sub-vertical shaft, and all these new machines had to be cut up in
1.5m x 1.5m pieces to get them down the shaft. Eventually we replaced
the sub-vertical shaft with a decline, and introduced a man-riding
conveyor (the first in South Africa) and a monorail system,”
says Dixon.
"Using locally manufactured
equipment will increase
productivity and employment,
and will drive down cost.
He adds that the mine also redesigned the
organisational structure. “Everything was
centred around the drill rig operator, who
worked alongside a Load Haul Dump
(LHD) driver who did the cleaning,
somebody responsible for the support
and a charger-up. We did away with
the seven supervisory levels in the
traditional mine. This requires a
total change in mindset, and it was
maybe a step too far for the older,
traditional miners.”
Lonmin, under then CEO Brad Mills,
had a great vision to mechanise
their platinum operations in the late
The problem at that stage, and it still
is today, is that machines don’t work
that effectively on inclines steeper
than nine degrees. Mechanising
thus often requires a mining
company to redesign the entire
infrastructure. It is difficult to
adapt existing infrastructure to
suit these big machines, and then
it’s very challenging to prevent
dilution. Part of the mechanisation
process, says Dixon, is to involve all stakeholders, including communities
and the labour unions.
Gold Field’s South Deep mine is one of the few mechanised underground mines in South Africa.
www. africanmining.co.za
African Mining Publication
African Mining
African Mining September 2019
39