Sizing Up a Fluid Situation
Fuel is always a major cost for mines – oil and grease, perhaps not quite so much,
but the wrong lubrication choices and applications can be expensive. Fuel-service and
lube vendors offer many product and service options to avoid problems, save money
and maintain asset health and performance.
By Russell A. Carter, Contributing Editor
And yet, the mission remains the same: To stay in business, they must put rock in the box, whether it entails loading hundreds of tons of rock and dirt by shovel into a haul truck for a trip to the crusher, or continual underground scoop, tram and dump cycles. In order to operate reliably, the machines used in either mining mode need fuel, oil and grease, along with filtration and fluids for cooling and perhaps even for exhaust aftertreatment as well. The OEMs that build these machines regularly update their new-product designs to provide easier serviceability and greater overall economy of operation, but each generation of engine, drivetrain and hydraulic-system improvements seems to bring stricter requirements for fuel quality and cleanliness, oil and grease formulations, and filter performance.
A Closer Look at Costs
When global economic events disrupt traditional
supply lines and future demand
for mined commodities becomes unclear,
mineral producers instinctively look for
ways to cut operating costs. In an industry
that routinely runs fleets of haulers burning
anywhere from 40 to 80 gallons of
diesel fuel per hour — loaded by shovels
with 4,000-gallon fuel tanks — fuel cost,
economy and storage/handling efficiency
often get spotlighted for management
attention. And as mines increasingly employ
larger but fewer trucks and shovels,
for example, the impact of taking a unit
out of production for lube-related service
often gets measured against the risks and
rewards of extending its service intervals
to minimize the loss of output. Increased
scrutiny of lube-related costs and consumption
might also lead to a closer look
at whether an operation is buying the most
cost-effective products, along with where,
how often and how much is being used.
This has become even more of a concern as technology progresses and the mining workforce evolves. Lubrication experts are quick to point out that misapplication or over-application of a product can cause almost as many problems as inadequate lubrication (see sidebar on page 38) and can often be attributed to lack of user familiarity and expertise. In fact, a 2019 study by Shell Lubricants UK indicated that mining companies lack confi- dence in their workers’ ability to cope with new technology. The survey revealed that many companies are concerned about the specialist maintenance requirements of new equipment (98%) and some believe they will face difficulties upskilling workers to use these new technologies (48%). Thirty-eight percent said they are currently lacking trusted external experts who could provide support in introducing “Industry 4.0” technologies.
Tonya Donaldson, Shell Lubricants global marketing director for mining, said, “It’s interesting to note that although 100% of those surveyed agreed that introducing these new technologies will have an impact on their choice of lubricants, only 46% feel they will need to place more emphasis on equipment protection and only 40% would focus more on longer oil life. Companies recognize that external support will be important to help improve maintenance practices, and 88% plan to use their lubricants supplier to help them progress.”
In another study conducted the previous year, Shell found that 60% of surveyed mining companies seemed to recognize that effective lubricant selection and/or management can help reduce costs. However, fewer than 10% of the businesses in the study understood that the potential savings can be six times greater than the expected average.
Basic Training
If worker inexperience or unfamiliarity with
a company’s commonly used lubrication
products are concerns, a focused effort
to clearly identify the various types of oil,
grease and other fluids used in its production
fleet or plant equipment might help along with providing fail-safe, reliable storage
and dispensing systems and installing
efficient, secure fueling-station equipment.
Lubrication labeling systems are available
from a number of sources. Chevron,
for example, offers its SmartFill Program,
a system based on a workplace organizational
methodology that originated in
Japan called 5S Visual Management. If
applied correctly, clear visual signals
throughout a facility identify where all
tools and supplies are supposed to be
located. These visuals range from simple
diagrams or labels to detailed process
flow maps and directional signs.
SmartFill comes with a customizable lube room chart to identify which lubricants belong in the storage area, and corresponding SmartFill labels in two sizes: large labels for bulk tanks, totes or large volume storage solutions, and small labels for hoses, top-off containers and component fill points. The SmartFill approach is to match the lubricant product displayed on the chart to the labels and assist in the “chain of custody” process. The lube room chart and labels should include the following: • Product name; • ISO grade; • Color coding and symbols for easy visual identification for top-off containers, fill points, etc. (optional); • Product hierarchy based on usage priority; • Supplier part number or internal part number; • Shelf life, which helps with first-in, firstout inventory management in the lube storage room; and • ISO 4406 Lubricant Cleanliness specification (optional).
Noria Corp., a lubrication consulting and training company, recommends that instead of using manufacturer brand names for tagging equipment and lubricants, companies should consider using codes from the ISO 6743 Lubricant Identification System (LIS). This avoids the necessity of retagging equipment and storage devices if operations lubricant suppliers change. Once labeled, lubrication products should be stored and dispensed with equal care. Whitmore Manufacturing’s new Lustor lubrication storage and dispensing system offer a scalable solution. “World-class maintenance and oil cleanliness requires processes and equipment that are both robust and easy to use,” said Doug Reid, vice president of product development. “The new Lustor line helps companies extend the life of their fluids with a compact, durable and easy-to-use unit that fits almost any industrial location. It provides high-quality filtration and the modular design allows customers to add on additional units to cover as many lubricating oils as they want.”
“Without protection, operational fluids are degraded, leading to higher fluid replacement costs and ultimately shorter life for the valuable equipment companies rely on. In the future, as machinery becomes more advanced, prevention and protection will be an even higher priority,” Vice President of Global Sales Joel Garrett said. The systems, according to Whitmore, are designed for customization and expandability. Three different configurations are offered: a wall mount with no reservoir, for use with drums or totes, and 65-gallon (250-liter) or 130-gallon versions. Optional equipment includes custom fluid ID labels, 3 µm or 20 µm filters, pneumatic 5:1 pump, spill containment and color-coded quick connects.
Another option for reducing the possibility of human error in lubrication applications comes in the form of automatic lubrication systems such as those offered by Graco, SKF, GreaseMax and others. Graco, for example, in January launched its Compact Dyna-Star (CDS) automatic lubrication system designed specifically for heavy-duty earthmoving machines in extreme work environments. The CDS controller can be paired via Bluetooth with a smartphone app to allow maintenance personnel to quickly monitor a wide range of lubrication metrics, including levels, pressure, configurations and more.
Graco said its automatic lubrication systems are now available as a factory option on a variety of Komatsu America’s earthmoving equipment. The automatic lubrication systems feature either a G3 Electric grease pump, MSP divider valves and a GLC-2200 controller, or an Electric Dyna-Star grease pump, GL1-X Injectors and a GLC-2200 controller. The system is also available as an after-market field install kit, which includes all the core components along with the necessary hoses, fittings, mounting hardware and protective guarding required for proper installation.
Longer Life
Potential lube-related savings can be uncovered
in a range of maintenance-related
areas, linked not just to the brand and type
of lubricants used, but also to increased
opportunities for extending the service life
of those products. In a case history focusing
on GE electric-wheel assembly lubrication
fluids, Donaldson Corp. found that
each rear wheel assembly on a haul truck
represented an initial cost of $250,000
or a replacement cost of $600,000. According
to General Electric, the expected
life of a rear wheel motor is 24,000 hours.
In order to achieve or surpass that figure,
fluid cleanliness is essential.
Another cost-related option that can pay off is the choice of whether to use synthetic or mineral hydrocarbon-based lubricants. As Total S.A., the French multinational integrated oil company, pointed out, synthetic lubricants are designed for specific applications and are usually more resistant to oxidation, the undesirable series of chemical reactions involving oxygen that degrade the quality of an oil. Although this means synthetics will likely last longer and lead to potential cost savings through oil-change interval extension, they are also more expensive than mineral-based oils.
Total regards its ability to identify opportunities that provide measurable value to its customers as an integral part of its continuous improvement process. This process involves the customer and Total working collaboratively to identify and implement targeted actions, including the use of synthetic lubricants when warranted over mineral products in relevant applications. After compiling certain baseline information such as current oil drain interval and average hourly energy consumption, Total processes the data using a Total Cost of Ownership (TCO) tool to identify lubricant performance levels and related cost to determine an optimal solution for the customer.
Although this process can point out opportunities for sizable lubrication-related savings to its customers, Total warns that certain variables can complicate the picture, such as: • Consistent contamination of a compartment containing a synthetic lubricant, making additional oil drains necessary and resulting in increased costs. • Overall energy savings achieved will depend on contamination levels as well as the number of subsequent oil drains needed to reduce equipment wear as a result of this contamination. In other words, the ultimate decision as to whether synthetic lubricants can replace mineral-based products should only be made after consideration of situational factors specific to each customer.
To support its customers that opt for synthetic products, Total Lubricants now has a suite of synthetic blend diesel engine oils especially designed for off-road applications. Total’s Rubia Works 3000 FE 5W-30 is an ACEA E6 product that provides high-temperature and high-shear-rate viscosity protection. The new oil, which Total said is suitable for most Euro Stage IV or U.S. EPA Tier 4f engines, is claimed to increase fuel savings by up to 1.47% compared to standard SAE 15W-40 lubricants. The Rubia Works 4000 range is formulated based on the API CK-4 performance classification to address severe duty operating conditions found in off-highway applications. The range consists of three premium heavy-duty engine oils: Total Rubia Works 4000 15W-40, FE 10W-30 and 10W-40. The products meet engine manufacturers’ SAPS (Sulphated Ash, Phosphorus and Sulphur) restrictions and help to extend diesel particulate filter service life. All major oil companies offer similar lines, including Mobil (Delvac), Shell (Rotella), Chevron (Delo), Sinclair, Castrol and others.
Finding Ways to Save
When it comes to estimating fuel usage
and setting fuel budget targets, mine operators
face continual challenges. Fuel
price and supply stability generally reflect
overall regional and global economic conditions,
but fluctuate significantly due to
localized supply, regulatory changes or
other related factors. Fleet fuel consumption
also can vary as mining conditions
change; a trend toward denser, heaver
material being mined, for example, along
with individual driver habits or adverse
weather conditions can have significant
effects. A study published by the Australian
government’s Department of Resources, Energy and Tourism on various
aspects of diesel-powered haulage at surface
mines reported that wet haul road
conditions can result in a 25% increase
in haulage fuel consumption compared
with hardpacked, dry road surfaces.
According to the company, the three most common fuel measurement strategies employed in mining include measuring at time of fill, Engine Control Module (ECM) fuel consumption estimations and on-equipment fuel measurement. The first two, said Cascadia, can provide useful information but suffer from specific drawbacks: In the case of ECM-based consumption estimates, the models constructed by engine OEMs to measure consumption can start out being quite accurate but can degrade in usefulness over time as an engine’s fuel injectors age and foul, fuel pressures vary and cylinders start to lose compression. Tank-fill consumption estimates can provide very precise information on the exact quantity of fuel dispensed to a machine and consequently consumed but lack the “granularity” to target specific characteristics of mining machinery and daily operation. For example, a typical fueling strategy might call for a truck to be refueled once per day. Over the course of that day, the truck might complete 50 haul cycles of various lengths, vertical travel and payload, might be operated by four or more individuals, and could be idled between 10% and 40%. Cascadia believes drawing accurate conclusions about the specific contributions of these factors to fuel consumption with a measurement frequency of once per day is not possible.
For higher measurement accuracy, Cascadia offers its SmartRView platform, derived from technology that the company obtained in 2019 by acquiring the intellectual property of Blutip Power Technologies, which offered operators of high-horsepower diesel engines a way to solve fuel challenges through its fuel-savings- as-a-service business. SmartRView is a real-time, cloud-based telematics system that provides fuel data and analysis via an on-equipment measurement approach. In addition to actual machine fuel consumption data, mine fleet operators need to know, at a minimum, how much fuel has been delivered, how much is in storage, how much is being dispensed and from where and when. In order to get a tighter grasp on fuel costs, industry experts generally recommend use of a fuel management system, either as a stand-alone product or as a module in a comprehensive fleet management system available from vendors such as Modular Mining, Hexagon and Wenco as well as OEMs like Caterpillar. (Modular Mining is a subsidiary of Komatsu and Wenco’s parent company is Hitachi Construction Machinery.)
Likewise, an efficient, safe and reliable fueling system setup can contribute savings in a variety of ways. Sara King, vice president of Wyoming, USA-based FlowTech Fueling, told E&MJ that her company’s Mobile Fuel Docks and Nonpressure Fuel Overfill Prevention systems can provide hard rock mining companies significant production gains with just a modest investment. King cited an example: In 2018, Flow- Tech built two 60,000-gallon Mobile Fueling Docks at a copper mine in Arizona. The docks, she explained, are extremely customizable and easy to relocate as future mining operations require. Each dock is capable of refueling eight haul trucks simultaneously at a rate of 130 gpm. The docks also have a fuel-truck fast-fueling station capable refilling the mine’s fuel trucks at 300 gpm. Fuel is filtered down to 10 microns before entering the storage tanks, and then to 5 or 3 microns before being dispensed. The double-walled tanks are equipped with an overfill prevention system to alert the delivery driver when the fuel level in either storage tank reaches 90% full. In the event that the fuel level reaches 95% full, an inline valve automatically closes, preventing the tanks from being overfilled. The fuel storage tanks are also equipped with a secondary tank monitor, which triggers an alarm if fluid is detected in the secondary tank. The copper mine customer reported that increasing the number of refueling stations while also increasing the flow rate at each haul truck refueling station from 60 gpm to 130 gpm yielded a six-month return on investment for the entire Mobile Fuel Dock project.
King said due to the increased flow rates at the new fuel docks, the copper mine elected to outfit its haul truck fleet, consisting of 35 CAT 793’s, with Flow- Tech’s nonpressure fuel overfill prevention systems. These systems eliminate tank pressurization during refueling and make it virtually impossible to overfill the fuel tank. She concluded, “Our Mobile Fueling Docks combined with our nonpressure overfill prevention systems make it easy to increase productivity without compromising safety and environmental profiles.”