international
construction
july-august 2013
QUARRYING
42
The big payback
Major Wire says its Double-Weave screening media, which is constructed of
two, side-by-side, light-gauge wires, outperforms heavy-gauge single-strand
wire screens and perforated plates in high impact applications because it is less
susceptible to breakages.
“The C120 cavity is also very well suited to crushing
fragmented feed materials. Even difficult feed doesn’t block the
cavity. Therefore, we hardly need to use our hammer,” he added.
Sundvik’s three-stage portable crushing plant is kept running
for two 8-hour shifts per day. The C120 jaw is usually operated
with a 100 to 150 mm closed side setting, resulting in a capacity
of 250 to 300 tonnes per hour.
The Boda quarry near the small town of Vrigstad, Sweden,
meanwhile features particularly hard granite, with a compressive
strength of over 300 MPa in places. Crushing specialist TJ Gräv
chose a Kleemann Mobicat MC 120 Z mobile jaw crusher as the
primary unit with a Mobicone MCO 11 S mobile cone crusher
for downstream work.
The primary stage reduces the feed material, which can be up
to 1 m long, down to a 0 to 200 mm stream. The cone crusher,
followed by a three-way screening system then produces 0 to
8 mm, 8 to 14 mm and 14 to 22 mm products. The plant is
producing 1,000 tonnes of material per day.
Tomas Johansson, owner of TJ Gräv AB, said the Kleemann
machines were was well-suited to the application. “Both plant
units have a diesel-electric drive system, which has a very
favourable effect on fuel consumption. Not only that, they are
built very sturdily,” he said.
It is also significant that TJ Gräv chose mobile crushing and
screening equipment, which is a clear trend around the world
due to the flexibility such machines can offer.
Mobile equipment
Hamilton Aggregate was founded in 2006 at Bonds
quarry, located in Clinton, Arkansas, US. From the outset
the company opted for mobile crushing
and screening equipment that could
be moved to the face to crush material
without the need for hauling it, and
which can be transferred between
quarries.
Today the set-up consists of a Sandvik
mobile QJ341 jaw crusher, a QE440
scalper, a QA450 triple deck screener and
an Extec X44 cone crusher. Extec is now
part of Sandvik.
As company owner, Edward Hamilton
said, “These mobiles are quality machines.
They provide us with lower operating
costs and high production for their size.”
A further quarry, Greers Ferry, operated
by the company in Higden, Arkansas,
was acquired to supply aggregates to a
nearby bridge project.
The constant steady supply required
from the Greer Ferry quarry emphasises
the need for a reliable aftermarket
support.
“The equipment has proved to be
highly reliable, but after discussing our
A Kleemann Mobicat MC 120 Z primary
jaw crusher tackles 300 MPa Swedish
granite at the Boda quarry near
Vrigstad.
