Spotlight Feature Articles WEAR PARTS & GET | Page 8

WEAR PARTS & GET
Africa, Qasim Abrahams.
Metso’s relationship with Kolomela was
established in 2010, when the global industrial
company provided the mine with the installation
and commissioning of its crushers and the
supply of OEM spare and wear parts. Other
Metso equipment on site include two Nordberg ®
MP800™ and one Nordberg ® MP1000™ cone
crushers.
The removal trays and carousel systems can
be used on any primary gyratory crusher – Metso
or third party. The site has approximately 30
secondary gyratory crushers in action, and
approximately 10 third party primary gyratory
crushers in action. The carousels need to be
matched for the applicable wear parts.
“While this was a known and tested concept,
this particular project required a completely new
carousel and removal tray design and also brand
new wear parts which included new concave liner
design, patterns and trial castings. Metso’s team
of experts completed this project in six months,
from customer order until delivery.”
Quick gains in primary gyratory
relining
Shutting down a primary gyratory crusher for
relining requires careful planning. The entire
shutdown process—from cleaning out the pit to
the final relining steps—can take days and, in
some cases, up to a week. Many of the tasks
involve safety concerns that need to be examined
and mitigated. To mitigate some of these
problems and speed up the overall relining
process, there are four solutions to consider.
Each has advantages in terms of safety
improvements and reducing downtime, but they
also carry certain costs that need to be
evaluated. Below is a quick overview of the
benefits of these options.
The outer lining of a typical gyratory crusher
consists of individual pieces called concave
segments; each one of these needs to be lifted
separately during installation and/or removal. A
60-89 gyratory crusher has a standard lining of
six tiers of concaves that need to be changed
during a planned shutdown event. Normally, all
the concaves would be removed piece by piece
and new concaves installed. Alex Merklein from
Metso’s Professional Services Team argues that
switching to concave segments with a different
design is a quick way to reduce both downtime
and maintenance. “The double-tier concave
segments are twice as high as regular linings.
This translates to 50% fewer consumable parts
to be changed, and ultimately reduces exposure
to risks for the crews performing the reline. The
same relining methods are used for double tier
concaves, so no additional tooling is required.
The double tier components can be slightly more
difficult to manipulate; however, the plusses
International Mining | SEPTEMBER 2019
often far outweigh any challenges in handling
the longer and heavier components.
For further improvements, using handling
tools to manipulate both the worn and new
concave segments for removal and installation
can bring even further gains. “In a large primary
gyratory, there can easily be 80 concave
segments to lift out and replace (4 tiers with 20
segments per tier). Not only is each individual lift
a safety risk, but it is also time consuming as the
pieces are lifted one by one.”
For removals of the older worn concaves, an
entire tier of segments can be lifted at the same
time using concave removal trays. This
significantly cuts down on the number of lifts
required. In the example with 80 concave
segments, this would cut the number of lifts from
80 to 4. The same logic applies to using a
concave carousel for the installation of the new
tiers of concaves. The carousel can be used to
install an entire tier of replacement concaves,
thereby also reducing the number of lifts from 80
to 4 for the entire installation sequence. By
reducing the number of lifts, risk exposure and
maintenance times are reduced.
“In terms of overall time, using these two
handling systems in combination typically cuts
reline time in half. Each carousel and removal tray is
custom designed to fit the specific primary gyratory
model and chamber profile. Investing in these tools
carries initial investment costs, but pays itself back
with increased uptime as well as improving safety
thanks to the reduced number of lifts.”
For customers who require the highest levels
of availability from their primary gyratory, there
is a third option to consider. Rotable top shells
are complete shell segments relined in advance
(either on or off-site) and ready to be installed
once the existing shell segments are removed
with their worn concaves still in place.
“This solution saves time as you do not need
to install the concaves during the planned
shutdown, and fewer components are being
manipulated during the outage period. It is no
longer necessary to transport and place work
platforms in the crusher and maintenance can be
done in a more controlled and safer environment.
During the shutdown, the shells are separated
and lifted (optionally with hydraulic shell
separators) and replaced with the relined shells.”
Compared to a typical shutdown period, using
the rotable top shell concept can provide a
reduction in downtime. Using rotable top shells
significantly reduces the time needed to reline as
well as requiring fewer labour hours and offering
improvements in safety by reducing the
likelihood of incidents or risks to personnel.
However, the flip side of the coin is that
additional shell segments are needed which
carry capital costs and also involve lifting
capacity considerations.
Finally Metso says a final factor to consider is
whether hiring a reline crew to perform the
shutdowns can bring further benefits. “Metso
Life Cycle Services (LCS) contracts often make
use of the above solutions, while also utilising
tools such as SMED (Single Minute Exchange of
Dies) analysis, which looks at each task within a
shutdown to determine where delays are taking
place to help determine where time savings can
be made. Over the course of the contract,
shutdown times often continue to decrease as
the SMED is a continuous improvement process
always looking for delays to be eliminated.”
Keech gears up in Tasmania with CEB
Keech Australia has been designing and
manufacturing high integrity steel castings for
leading companies around the world for over 85
years. To support a growing range of products for
its domestic and global customers, Keech has
supplemented its sales and support offices on
the Australian mainland with first-class suppliers
and distributors in key locations, including
Tasmania. Coastal Engineering & Belting (CEB)
was selected as Keech’s Tasmanian distributor to
service the state’s significant mining and
industrial sector, as well as CEB’s many
customers across Australia. The partnership has
enabled Keech to supply and support its
comprehensive range of replacement GET
including Wearpact™ lip assemblies, adaptors,
tooth points, blades, quick change, wing
shrouds, heel blocks, side cutters, ripper shanks
and boots, cutting edges and grouser bars.
“CEB is a specialist firm with highly skilled
professionals in general engineering and metal
fabrication. Being strategically located in the
heart of Tasmania’s mining region, the company
has built an international reputation in the
mining sector, and now services equipment and
builds buckets for mining companies in Tasmania
and across the key mining areas in Australia and
PNG. The appointment of CEB as its exclusive
Tasmanian distributor has been a clear win for
mining customers using Keech’s proven
Wearpact™ bucket lip assemblies.” Wearpact™
is a patented ground engaging tool designed for
both underground and open pit conditions and
has a 19 year history of reliability on mine sites
around the world. The system attaches to the lip
and base of buckets in any configuration and
size, and is uniquely designed to reduce edge
wear and enable fast and efficient replacement.
CEB plays an important role promoting and
fitting Keech GET components including Keech
Wearpact™ lip assemblies to new and
refurbished buckets for customers across
Australia and around the globe, including BHP
Olympic Dam in South Australia, Fosterville Gold
Mine in Victoria, Cadia Gold Mine in New South
Wales, and Porgera Joint Venture in Papua New