SCREENING AND WASHING
To get an in-depth insight into some key questions on screening technology
and strategy in the mining market, Paul Moore spoke to
Corné Kleyn, Global Product Manager - Screens at Weir Minerals
Q Is it fair to say that the basic design of vibrating screens, whether
dewatering, banana or horizontal, is similar across all the majors eg
Metso, Haver, Weir, Joest etc? This being the case what differentiates OEMs
today, is it the right customised design for the material, the right screen
media or other aspects such as reduced energy usage with the right drive,
lower noise, lesser footprint etc?
A The fundamental design of screens is the same, but within Weir Minerals
we are capable of changing certain elements of the design to suit the
customer’s specific circuit in which the screen operates. It’s also important
for OEMs to manufacture a wide range of screening products to offer
mining companies because no two sites are the same. They all have
different problems and requirements, and it is important that OEMs can
cater to this. At Weir Minerals, we have the screening solutions for our
customer base with both the Enduron ® and Trio ® product ranges, from
double deck banana screens to dewatering vibrating screens. We pride
ourselves in material technology and our patented material components
such as our rubber compounds, some of which are formulated for screen
media. Our Linatex ® brand is well known within the industry for
representing our long lasting rubber. We have some standard screen media
compounds avai lable across the globe but bespoke configurations are
available on a regional basis. One of the biggest differentiators in my
opinion would be OEM application knowledge and experience. You need to
ensure the equipment offered is suited for the application specified, but
being part of the customer’s process and involving yourself in their day-to-
day business is what would set Weir Minerals apart from the competition.
Lastly, what differentiates certain OEMs is the utilisation of new
technology including intelligent monitoring. Weir Minerals’ advanced
Synertrex ® monitoring system platform is a great example of the
enhancements which can be made to our products through intelligent
monitoring. We have successfully trialled the Synertrex ® platform at
various customer sites across the globe and it will soon be made available
to the market.
Q Is the mining industry as in other equipment areas now trying to keep
existing screens running for longer with maintenance/service rather than
having to buy new screens? Being a robust steel product is there also a
market in used screens from closed mines?
A This is a topic that we are constantly discussing with customers.
Commodity price drops and a decline in market demand have put a strain
on operating profits. This has led to reduced budgets for capital equipment
as mine owners are struggling to keep their mines running. We have found
success with employing Aftermarket Product Support Specialists in our
sales regions, offering regular equipment audits and ensuring our screens
run optimally. If “out of specification” conditions are picked up early
enough, failures can be prevented. I believe that going forward OEMs will
start packaging screens with Condition Monitoring systems as part of the
offering. At one of our Synertrex ® trial sites, we have proven the value of
real-time condition monitoring. We predicted an imminent failure and
responded proactively by replacing the defective component, thereby
avoiding an unplanned shutdown. Regarding the use of “second-hand
screens”, this is uncommon in the mining environment and relates more to
short-term project and quarry clients.
20 International Mining | OCTOBER 2017
Q Are lifetime service contracts for screens becoming more common?
A We have found that customers are eager to sign $/t contracts. This
implies that the OEM gets reimbursed a rate per amount of material
passing through their equipment. At Weir Minerals these contracts put full
ownership of equipment and its operation on us. We put this package
together based on our customers' needs.
Q Do mines commonly buy OEM screen media to start with then later try to
switch to a cheaper option?
A The majority of the time, the customer will purchase the screen
“complete” including drives, screening media, wear-lining etc. For
replacement screening media, many customers have contracts in place
with media suppliers, so they would purchase directly from them. If the
OEM’s screen media is of high quality and proves its longevity to
customers then they will not be looking for the ‘cheaper’ option. We find
this to be the case with our Weir Minerals customers.
Q Would you say the core demand in screens today is from a particular
commodity such as iron ore/coal or gold/copper?
A The market is volatile at present and there is general investment
uncertainty. Coal has always seen steady demand, since the demand is
created by the need for energy generated by existing coal-fired power
stations. Iron ore has seen a marked drop due to past oversupply, and
over-capitalisation due to artificial demand. Gold and copper demand is
normal and on the rise. Utilisation of screens is directly proportional to the
production throughput of the application.
Q Are you working more directly with mines in screen design and selection
whereas before EPCM companies would be making decisions on key
process equipment?
A At Weir Minerals we work with both EPCMs and mine companies. In
recent years, mining companies have started to rely on OEMs to assist with
screen selection and design, but this is mostly due to the shift to a
“brownfield” project environment. Mines are constantly trying to optimise
their operations to increase profits. For products such as screens, mining
companies may ask us to optimise to suit their needs, and this is an
important part of our solutions offering. When more “greenfield” projects
get underway, EPCM companies will once again be involved.
Q Is screening competing with alternative equipment in some cases or in
most applications is there no alternative?
A In very fine screening (<200 μm), you could compete with hydrocyclones.
For larger applications, “traditional” screening is still the accepted method
of mineral separation. For dewatering applications, various alternatives
exist including filter-presses, trommels etc. It completely depends upon
the customer’s requirements and we work with them to provide the right
solution, be that screening or hydrocyclones.