Spotlight Feature Articles Joy Global Drilling & Loading Apr17 | Page 8

DRILLING AND LOADING
Liebherr R9150 proven in Siberia
Liebherr recently introduced its R9200 mining
excavator, fitted with the Liebherr advanced
bucket and GET solution, and equipped with a
16.3 yd³ bucket capacity, which offers the biggest
payload in its class. This new 200 t machine is
designed to match mining trucks with payloads
of up to 140 t and provide maximum uptime since
it features superior reliability and easy
serviceability. “In addition, the cutting-edge cab
provides the operator optimal comfort and safety
due to its large panoramic windshield, armour ed
glass and low noise level.”
However, the R9150, launched in 2012, has
been proving its worth in extreme conditions.
ALROSA mines the Udachnaya kimberlite pipe,
an operation which is the largest, both by scale
and reserves, in Western Yakutia, Russia. The
working conditions and the climate at this site
are extremely harsh as mining is being done in
permafrost ground where temperatures vary
from -55°C to +40˚C. Working in these
environments affects all types of mining equipment
extensively: standard fabricated rubber products
soon get brittle while working fluids thicken and
steel reaches its strength limit at -50°C.
Located far away from cities and basic
infrastructure facilities, the Udachinsky mine can
only be reached via air or temporary winter roads
that are carved from snow and ice. As there is no
fast way of getting to the mine, the delivery of
equipment, spare parts and maintenance
materials can be complicated.
The transportation chain at the Mining
Processing Plant Udachinsky GOK is based on
mining trucks with a capacity varying from 40 to
136 t. Predominantly these trucks are used for
the removal of overburden and the transportation
of kimberlite. To ensure the mine’s continuous
production, mining equipment is working on a
24/7 basis. This requires very efficient loading
tools that are capable of handling no less than
20,000 t of material per day. Extremely reliable
and highly efficient excavator requirements
means that the company imposes very strict
specifications for each new piece of equipment.
Therefore, in order to meet ALROSA’s
requirements, a Liebherr R9150 mining excavator
was chosen to fulfil this challenge. Once the
Liebherr R9150 mining excavator was delivered to
the ALROSA mining site in 2014, the machine was
commissioned and successfully passed tests in
these severe conditions. As well as the freezing
climate, the mined material is an additional
challenge for the equipment, as kimberlite is one
of the hardest and most abrasive types of rock in
the world.
This leads to intensive wear on the excavator
parts such as sticks, booms, buckets and tracks.
This R9150 is equipped with an 8.3 m 3 heavy-
duty backhoe bucket specially designed for
International Mining | APRIL 2017
Liebherr R9150 Mining Excavator at
ALROSA’s Udachny kimberlite
(diamond) mine, Russia
The pre-heating of the machine is possible
thanks to the use of a genset located on the
ground. This avoids the genset being subject to
machine vibrations and also allows the customer
to use it easily elsewhere in the mine site.
Cat Operator Assist and Latch Free
Dipper
handling hard, abrasive and frozen rock. This
bucket is exceptionally durable and resistant to
wear: it penetrates the material with ease and is
characterised by a very high fill factor. In
addition, larger track pads have been mounted
on the undercarriage of this R9150 to reduce the
applied ground pressure and also provide better
machine stability during operation. To minimise
downtime and damage, the machine is also
equipped with a piston rod guard for the bucket
cylinder. This robust steel cover protects the
cylinder from being damaged by falling rocks.
Throughout operation, the R9150 proved to be
a highly reliable and productive machine capable
of withstanding extreme environmental conditions
and continuously working on a 24/7 basis.
Although this R9150 mining excavator is digging
hard material, it loads a 136 t dump truck within
just seven passes, while the average duration of
one cycle time is 24 seconds, resulting in a very
high monthly production of 250,000 m 3 , which
represents over 90% of machine availability.
For Russian operators it is also crucial to be
able to start the engine at temperatures as low
as -50°C, sometimes even lower. To meet the
customer’s requirements, Liebherr provides
specific climate solutions for its equipment, in
the form of an Arctic Package. This kit comprises
a broad array of devices that ensure easy start up
and consistent and uninterrupted work at
extremely low temperatures.
The operator comfort is optimised thanks to
the various additional options installed inside the
cabin. To maintain warm air, the driver has access
to additional heating, better cab insulation,
double glazing and front and side window
defrosting. To avoid the cooling of the engine
compartment during machine downtime, a
special connection with a duct below the engine
and the splitter box allows warm air to be
brought from an external heater. The Liebherr
Arctic Package also offers a pre-heating system
for hydraulic oil, fuel and engine coolants,
specific cold temperature fluids, and also
includes insulation of heating hoses in order to
reduce the dissipation of heat.
For mine operators, keeping an electric rope
shovel in the bank is essential for optimum
productivity and profitability. Recognising this
vital requirement, Caterpillar has developed the
Operator Assist – Enhanced Motion Control
system, standard on new 7495 Series shovels
and available for certain Cat ® 7495 and Bucyrus
495 shovels already in service. The new software
is designed to simplify machine operation,
allowing the shovel to be operated in a manner
that both promotes high production and protects
the machine from inadvertent misuse. The new
system can enhance production by reducing the
occurrence of operating faults, such as crowd
over-speeds and boom jacks.
Depending on the specific digging practices
followed in the mine, the Operator Assist –
Enhanced Motion Control system can yield a
number of significant benefits, including more
reliable crowd rope replacement schedules, full
design life for hoist ropes, reduced wear on
crowd brakes, and longer life for hoist gear case
components. By intelligently controlling machine
motions under certain conditions, the system
reduces downtime for maintenance and repair.
This translates to added production and lower
cost per tonne, with a return on investment
typically less than six months according to
Caterpillar.
When developing the system, Caterpillar
engineers reviewed the operating habits of
numerous operators of all skill levels. Based on
this practi cal information, the new system
addresses specific operating situations that
could potentially jeopardise both the machine
and the production schedule.
Over-crowding the dipper and excessive
loading can stall the dipper and place detrimental
forces on hoist gear-case components. The
system monitors force and optimises
crowd/retract commands in relation to hoist
speed. Optimising the loading cycle reduces
stress and wear on hoist system components.
The Operator Assist—Enhanced Motion
Control system is available for three 7495
machine classes: 7495 (ER601143 & up); 7495 HF
(ER801136 & up); and 7495 HD (ER701167 & up).
The control system software update typically
requires only two hours.
The Cat ® LatchFree™ Dipper System is the
first successful solution to the most common
cause of rope shovel downtime. The system
replaces the standard maintenance-intensive