In conversation with
holes for pre-strip drilling. Our hole diameter varies between
127mm for the smaller pre-split holes and 331mm for waste
drilling. The ore drilling diameter is 251mm.
Extra axillary equipment (mostly Komatsu) include a total of
six dozers (three Komatsu 475s and three Komatsu 375s), four
wheel loaders, also Komatsu (WD600), plus three Komatsu
825 graders and four PC850s for clean-up work and digging
trenches. We also have additional support equipment to move
the electric cables and infrastructure.
chemical reaction that takes place during this stage results in
the uranium that is in the solution being attracted onto resin,
and then, through a series of chemical reactions, that solution is
concentrated. This solution is then passed on to the final product
area where it is precipitated into uranium and then packaged as a
final product through a fully automated packaging process.
Because of the high radiation, the packaging is done in a fully
enclosed environment where the product is drummed and sealed in
containers, which is taken directly, by road, to the Port of Walvis Bay.
The entire fleet is designed to move between 100 million and
120 million tonnes per year. Our production profile currently
for this year is to move 100 million tonnes with a complement
of just under 490 people. Given the size of the equipment and
the distances covered, our fleet is installed with a Modular Fleet
management system that manages, monitors and controls, and
ensures efficiencies of our fleet. Where does the mine get its water from?
Will the mine continue ramping up in the next two to three years? It is a risk. If Trekkopje decides to commence with its mining
operations, we will have a water supply challenge. The quantity
of water that we require, currently only they can supply; we don’t
have enough capacity from local sources. So yes, it is a significant
risk for us. We are, however, working at mitigating that risk.
NamWater has the same problem.
We are currently targeting 10 million tonnes per year of ore in
the short term, ramping up to 15 million tons of ore over the next
three years. On average, the life of mine feed to the processing
plant is 15 million tons per annum (currently it is 10 million per
year). The feed grade ranges between 500 and 600 parts per million
(ppm) over the life of mine.
Can you tell us more about the processing plant?
We have five main facilities: the primary crusher; the milling
circuit; the leaching unit; the counter current decantation (CCD)
and the ion and sulphate exchange; and then the final processing
and recovery area.
The ore is dumped by the mining team into a gyratory crusher (4 000
tonnes per hour). The crushed material is then fed onto a course
stockpile via an overland conveyor onto a covered coarse ore stockpile
with a capacity of 190 000 tonnes. It is then reclaimed through
reclaim feeders into a semi-autogenous grinding (SAG) mill before
transferring into a ball mill. From the ball mill, the undersize reports
to six screens, which then separates the material into the correct
size distribution for the leaching stage. The undersize reports to the
leaching circuit, while the oversize is fed back to the ball mill.
Up to that point, the aim is to reduce the size of the material that
is small enough to liberate all the uranium, between 0.6mm and
0.8mm. In the leach area, there are 10 leach tanks in which the
slurry is mechanically agitated with blades. In the tanks, we add
acid and other chemicals to the slurry to dissolve the uranium.
The slurry is passed on to the CCD, which is the sequence in
which the material is fed from the leaching tank versus settling;
in other words, a solid liquid separating process. The solids which
now contain very little uranium, settle at the bottom and are then
pumped out to the tailings dam.
The solution is then passed on for clarification where impurities
are eliminated. From there, it is fed to the ion exchange. The
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Our water is provided by the government entity NamWater;
however, they source most of the water from the desalination plant
built by Orano (previously Areva). The plant was originally built to
provide the Trekkopje uranium mine with enough water.
Do you not regard it as a risk to be relying on water that could
one day be used by Trekkopje if the mine re-opens?
There will be a serious problem if all the uranium mines in this area
start operating at full capacity and all need water. Uranium mining is
water intensive and to source enough water in a desert environment
is problematic. We use about 0.6 cubic metres per tonne. This is all
part of the risk that we need to evaluate and assess.
Should the mines and the authorities not start thinking about
more desalination plants?
There are discussions about more desalination plants.
And the electricity supply?
We get our electricity through the national grid from NamPower
and do not experience any problems, but we also generate our
own electricity on site. The mine has its own acid manufacturing
plant and we use the steam generated by the process to drive a
turbine that produces about 15MW capacity. In addition, we
have nine 10MW installed diesel generators. The diesel is only for
emergencies, though.
What maintenance regime does the mine follow?
We do our own maintenance, with the support of the original
equipment manufacturers like Barloworld (CAT), Komatsu,
and Atlas Copco. Our in-house team looks after the processing
plant, maintenance, and our mining maintenance. There are
several workshops on the mine site, including a workshop for
drill rigs and trucks as well as auxiliary equipment. There is
also an electric workshop, a boiler workshop to attend to all the
mining equipment, and then likewise, in the processing plant,
we also have communition, slurry, and electrical workshops to
support the plant. b
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