FEATURE
CHOOSING RIGHT PLANT
AND EQUIPMENT
IS KEY TO SUCCESS
By Eamonn Ryan
Selecting plant and equipment can lead to success in an aggregate market where selling
prices are typically inflexible and highly competitive. Cone crushers and feeders often
have a lifespan of 30 years or more so it is not easy to change buying habits; therefore,
maintenance is frequently the deciding factor, along with price and quality.
E
fficient crushing and screening are
the best methods of dropping the
overall cost per tonne on a plant but,
sadly, it is often the most neglected facet
faced by inexperienced plant owners.
Picture a 100t per hour plant, where the
correct screen could make a 2% difference.
In a five-day, seven-hour-a-day operation,
that’s an additional 70t of production a
week, or 14 tipper truck loads a month for
the same overheads. Cheaper equipment,
such as meshes on screens, can result in
more downtime and loss of production.
To execute the crushing process cost
effectively, it’s necessary to choose the
correct crusher for the application as
this saves time and money over the long
term. As Osborn indicates in an article
in this issue (Business, page 11) the size
and geography of the site determines the
configuration of the feeder.
Max Bajkay, Metal’lum marketing
manager, explains that the most important
determinants in choosing a crusher are the
strength, size and shape required of the end
product. All tooling deliberations such as
the most economical crusher for the job at
hand, must be informed by the quality of
the final product at the end – whether the
end product is, for example, filter sands,
road construction or asphalt topping.
22_QUARRY SA| JULY/AUGUST 2019
With crushing, you start with
the end
The McCloskey J45 high capacity Jaw Crusher.
“Once quality is determined, the process
is to go step by step from the end process
to the primary crushing stage. The final
product requirement is the cornerstone of
equipment selection and plant design, and
particular combinations of jaw crushers
and secondary crushers have proven more
effective in achieving desired outcomes,”
says Bajkay. That final product also governs
the grading envelope that must be achieved
(or the ratio between coarser and finer
aggregates). The intended throughput rate is
another key consideration in the choice of
crusher and its size.
The size of the run of mine (ROM), the
strength of the material and the desired
product shape determines how many
crushers and crushing ratios are required
to crush the ROM to achieve the desired
product sizes. An impact crusher, for
example, will be required to achieve a high
quality shape specification.
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