May 2017 www.coalage.com 29
moving overburden continued
"After about 15 minutes, we had to
hold the trucks up for 4 minutes while the
shovel catches back up," Pitchford said.
"The good news is that the shovel never
stops loading. In the first 20 minutes, the
surge production outpaced the traditional
method substantially."
Some incidental benefits for the tech-
nique have been identified that primarily
result from not dropping 100 tons in the
truck bed. "You're no longer shock loading
the driver," Pitchford said. "It also relieves
stress on the shovel operator."
Basically, the mine should see the fol-
lowing savings:
• High volume due to precise truck fill
factors;
• Savings on operating expenses due to
reduced truck fleet;
• Truck body wear and damage is re-
duced; and
• Tire life should increase with cleaner
pit floors.
After operating for 20 hours (two 10-
hour shifts) with one rope shovel and a
dozen trucks, MMD can show an addi-
tional 1,400 tph more than loading in a
conventional manner. "If you adjust the
Arena software so that both systems are
producing the same amount, the software
shows that a mine could eliminate two of
the trucks," Pitchford said.
MMD has not built a Surge Feeder
yet, but they have six of these machines
out for bid with major mining companies.
They believe the first will go to a copper
mine in Chile.
SEE US AT
LONGWALL USA,
BOOTH #542
The Surge Feeder would be positioned between the shovel and the truck. The feeder is
continuously processing the rock that the shovel dumps into it as the trucks queue. They never
reverse into position.