Modern Quarrying July-August 2015

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FACE TO FACE WITH
ASPASA
be choke fed for optimum performance. It
is therefore vital that feeders and screens
deliver the right amount of materials to
the crushers at all times. Moisture should
also be kept to lower than 5,0%, fines and
the use of water minimised to avoid wear
on liners from the bottom. If you screen
right, your crushing is right,”Fletcher says.
It is always advisable to run a plant at
100% for less time, rather than running it
on trickle feed for a long period of time, as
the lowmaterial levels may cause damage
to the crusher.
Any crusher works better when full.
Equally important is the selection of the
right type of liner with the right type of
profile to feed materials and ensure the
correct movement within the process.
Depending on the application there are
coarse to fine profiles that can be speci-
fied to meet crushing requirements.
According to Fletcher, maintenance
staff should monitor the wear pattern
regularly to ensure it is even from top to
bottom and also ensure that the liners are
replaced at 25-40% of their thickness to
prevent damage to the machine.
“They should also look at the wear
pattern to ensure crushing is taking part
April
across the entire section, which deter-
mines the overall utilisation you are get-
ting out of crusher. Reputable companies
will be able to look at a liner and tell you
the effectiveness of crushing taking place
and be able to develop liners to address
inefficiencies.”
Active representation
Pienaar has once again been appointed to
the executive council of the Chamber of
Mines, and is also involved with the MHSC
which is chaired by the Chief Inspector of
Mines. This tripartite body comprises the
unions, the state and employers.
Pienaar is an alternative on the
Council, chairperson of the HR Committee
and an alternative on the MRAC
Committee, which oversees draft legisla-
tion as it comes in from the various task
teams.
Aspasa is more than a voice for
industry; it champions the interests of
its members and Pienaar says the issues
it is fighting for are aimed at providing a
sustainable, responsible and professional
industry. MQ
Report and photographs by Dale Kelly
Regulation 292 in which speed limits will be reduced to 40 km/h
in urban areas, 80 km/h outside urban areas and 100 km/h on
highways, where they pass through urban areas, is also being
challenged. The objection raises the point that heavy vehicles
cannot operate within their optimal efficiency at 40 km/h with a
load and tend to overheat.