MINE EXCURSION
reduces the ore to minus 6mm. The material is fed through the
primary crusher on the western side of the D567 bitumen road
that dissects the mining area from the processing plant. Once
through the crusher, a 300m long belt conveys the crushed
rock in a tunnel underneath the road and delivers it to the
secondary crusher, which is located east of the road. After the
three crushing stages, the material is fed into a primary mill,
which reduces the size further to 80% passing150 microns. The
separation process involves an oxide fl oat rather than a sulphite
fl oat, which is normally used in conventional fl otation in the
gold, platinum, and base metal industries.
Unique fl otation process
The fl otation process at Nokeng uses specifi c chemicals and
reagents, and according to Brits it comprises several additional
fl otation steps to upgrade the ore in order to achieve the
desired product.
“The fi rst stage is known as rougher fl otation; after that, the
ore goes through a further six stages of cleaner fl otation. The
cleaner tailings are reground and re-fl oated. This product joins
the mainstream acidspar circuit. The re-fl oat tails and fi rst cleaner
tails are processed and used to produce Metspar, a lower-
grade fl uorspar product. The acidspar at Nokeng has a grade of
97.2% calcium fl uorite. This is fi ltered to contain less than 10%
moisture, and the premium product, which is our acid spar, is
Nokeng is currently mining and crushing ore from the Plattekop deposit,
west of the processing plant.
"The material is fed
through the primary
crusher on the western side
of the D567 bitumen road that
dissects the mining area from
the processing plant.
Material is fed into a primary Sandvik jaw crusher. There are three stages of crushing at Nokeng.
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African Mining Publication
African Mining
African Mining November 2019
25