A LOOK INSIDE NEW TURNS FOR COAL MINING LUBRICANTS AND FUELS
By Donna Schmidt, Field Editor
They are the literal lifeblood of mobile mining machinery — the fuel that makes them run, and the lubricants that ensure they run well and meet the industry’s harsh demands.
Machinery doesn’t sip fuel and can be extremely tough on even the most robust lubricants. According to data provided by Quaker, one truck uses 28 gallons of fuel per hour, based on an eight-hour operating time. Depending on spoil removal, it can run, at times, 20 hours a day, with maintenance time between shifts accounting for the other four hours. It also uses 220 gallons of grease daily through automatic lubrication systems, and will normally use 50 gallons of hydraulic fluid per day with small leaks; it can use hundreds of gallons if there is a major failure. Some large mines may run a fleet of 20 or more trucks on a site.
An average shovel or dragline uses 4,000 gallons of grease in just two weeks through automatic lubrication systems, Quaker said.
An average longwall will use 3,000 gallons of emulsion oil a month, which only accounts for 2% of the total mix; the other 98% of the mix is water. This amounts, according to data collected, to a total of 150,000 gallons of mixed emulsion fluid per month. The longwall also uses 500 gallons of hydraulic oil, 500 gallons of gear oil and 700 lb of grease per month.
According to Alfa Laval, and using haul truck operating hours of 5,400 to 6,000 hours annually and excavator use of 7,000 hours annually, a shovel or excavator can use as much as 525,000 gallons per year with load factors between 70 and 80%, and a truck will use almost 300,000 gallons per year.
Efficiency, emissions and costs are just a few of the crucial points that can have a big impact on a miner’s bottom line if not considered carefully.
|On average, an excavator burns 525,000 gallons per year and a haul truck will burn 500,000 gallons per year.|
Making the Most of Budgets
Speaking of the trends it has been seeing from operations regarding procurement and storage of lubricants and the methods being used to make the most of budgets in this area, Quaker Application Specialist Glenn Lilly said the mistake some make in their cost-conscious search for the least expensive product is sacrificing quality for price.
“Storage of materials to some customers is important, and they store it in proper containers, and use the stock in the order it arrives so the products do not become outdated; they also stock as few items as possible,” Lilly said.
“For instance, if one grease fits multiple needs, they will buy and stock this grease versus stocking multiple greases. This means that sometimes a higher quality item is used where the high quality is not needed, but it meets or exceeds what is called for, so it works.
“However, this also means that sometimes a lower quality product is used where it does not meet the needs of the application, which creates more problems in the future. Seldom will the client buy and stock more products than what they think they will use. This often means running out of supplies and calling on emergency short-time deliveries. This is where the pressure lands on the supplier-vendor. When possible, they will buy bulk, which is cheaper versus smaller packaging and volumes.”
Quaker officials are also quick to stress that there is no substitute for maintenance and regular evaluations of lubricant efficiency.
“Scheduled preventive maintenance is the second most important thing you can do. Keeping the schedule and performing the maintenance is the most important. Often this is hard to do, as meeting production goals often takes precedence, but without proper maintenance the production will not happen,” Lilly said. Adding that proper sampling and testing of fluids and lubricants is a mine’s key to being aware of what’s going on with a piece of equipment.
Some questions to ask: Is the lube performing properly and not failing? Is there a problem in the gearbox starting to occur as metal shavings appear in the sample? Is my fluid still mixing with my water properly as my water is changing?
“Our field associates regularly take samples and run analysis to monitor the performance of the fluids and lubricants to make sure the equipment is able to run in optimal conditions. Vendor service, testing and evaluations are essential, and customers expect it.”
Proper filtration also means everything to the life of equipment and fluids, the company said, and it is a ripple effect. Engines depend on oil and fuel and air filters, hydraulic fluids depend on filtration, proper filtration increases the life of the equipment and the fluids, and increased life means increased production and profits, and decreased costs.
The top recommendation Quaker can make to save money and time while keeping a mine safe and meet goals is knowing the right solution for an issue. “Mines and facilities must buy the right lube for the right application; using an inferior product because it is less expensive only increases your cost in the long run,” he said. “Utilizing your supplier’s knowledge as to what lubricant fits the application best should be taken advantage of. The mines and facilities should evaluate where the product will be applied, the conditions it has to operate in and abuses it will have to endure, and then use the best product for that application.”
Quaker also recommends that mines use fire-resistant products whenever and wherever possible. “The cost is a little higher, but we remind the customer, how much would a fire cost? How much is a little insurance worth? Choosing a fire-resistant product only pays off in the long run. Safety should always be the most important thing in any manager’s mind. Cutting corners and cost should never take precedent over worker safety.
Commodity vs. Specialty Lubricants
Procurement of lubricants, in particular speciality lubricants, is still highly fragmented and mainly takes place at a plant/mine level, according to Daniel Narnhammer, head of Global Com-
petence Center Mining for Klüber Lubrication. The reasons are threefold: the small purchasing volumes compared to fuels and commodity lubricants; the decision of which lubricants are used is often made by the plant or maintenance officer directly, as he knows the requirements of his equipment best but does not take care of reducing the product types in use; and that various current and upcoming global regulations like REACH, GHS, and EAL will make it difficult for the purchasing departments in the large global mining companies.
“It is important to partner with a lubricant supplier that has the ability to develop and register its products in line with laws and regulations [and] extensive application know-how paired with the chemical/lubricant background is the basis for lifting synergies or using similar products for a variety of applications,” he said.
The hot topic of emissions, Narnhammer said, is not exclusive to fuels and fuel consumption.
“The emissions of a haul truck is determined by several factors, such as the engineering of the combustion engine, drive train, and gearbox efficiency factor and lubricants used. Energy consumption reduction strategies can analyze test rig testing, simulation and calculation under real-life conditions, including energy consulting, measurement, evaluation and reporting.”
Those facilities with their eye on compliance and being a good neighbor are also, in many cases, those also exhibiting the tightest uptime and production efficiency plans for its crews and its periodic production and safety goals. Keeping that in check means working safely as well as intelligently, and Klüber’s position on those recommendations for mines is straightforward.
“One simple answer: change from commodity lubricants to specialty lubricants. For example, changing a haul truck rear axle gear oil from mineral oil to high-performance polyglycol oils will extend oil lifetime up to five times. This leads to reduced equipment downtime (caused by less maintenance efforts), longer MTBF and less fuel costs. Last but not least, lower gear oil costs due to longer oil lifetime.”
As an example, Klüber Lubrication recently switched a ball mill drive from a standard open-gear product to transparent Klüberfluid C-F 3 Ultra. The consumption of conventional commodity open gear lubricant was 500 grams per hr.
“We could bring this amount down to 90 grams per hr, which resulted in lower lubricant costs, reduced disposal costs and lower pinion and girth gear temperatures,” he said of the results. “Additionally, the manpower utilization could also be reduced, because the clogging of the drainage system was no longer a problem.”
He also noted a case where a facility worked with the company to switch over to a rotary screw compressor in a mining operation from a mineral oil to Klüber Summit SH 46, and the oil change interval prior to the changeover was 4,000 hours.
After the changeover, the oil lifetime reached 8,500 hours and resulted in a 1.5% energy savings, he said, which resulted in a bisection of the annual oil consumption from 120 liters to 56 liters per compressor.
On the product front, Klüber introduced a multipurpose lubricant for extreme high-temperature applications in July to offer its customers with even greater corrosion protection and high evaporation stability.
Klübertemp GR AR 555, developed for high-temperature applications up to 250°C and applications exposed to aggressive media, is a white, homogeneous long-term grease based on a perfluorinated polyether oil (PFPE) and polytetrafluoroethylene (PTFE).
The product, which is NSF H1-registered, has several potential applications including pillow blocks/bearings, seals, rotary joints and ball bearing chains.
|Alfa Laval offers an automatic fuel filter that automatically self cleans, ensuring clean fuel and reduced maintenance costs.|
The Importance of Filtration
Theodore Esplin and Fabricio Navarro, manager of OEM engine and transport and regional business manager filters, Americas, respectively, for Alfa Laval, said the area of emissions has been a major one for its business and the clients it works with, and is easily considered the top trend looking ahead.
“New engines meeting the latest emissions requirements are requiring cleaner fuel in order to operate properly and reliably; therefore, the mines are [implementing] better filtration systems not only on the vehicles but throughout the fueling system,” Esplin said.
“Typically there are filtering points all along the way from when the fuel is delivered to the mine site and goes into bulk storage. It is filtered to a certain fineness, then when it leaves the bulk tanks and gets pumped to the actual fueling station it is filtered. Then when it gets pumped into the vehicle, it is filtered, then on the engine it has very fine filtration. All along the fuel supply chain, these filters need to be regularly replaced and the old ones disposed of.”
The process is a costly one and can become involved, from procuring replacement filters to managing regular scheduled maintenance to disposing of the used filters.
“It’s an area that still can be addressed,” he noted, as mines are switching to longer life filters; however, at the finer filtration levels, these can be quite expensive and still require frequent change-outs. Because of that, there are opportunities present now to address this need with changing technologies.
For instance, according to Navarro, centrifuges used in the marine and stationary power industry to clean the fuels and automatic, self-cleaning filters are also used in these same industries. These technologies eliminate the need for frequent servicing and greatly reduce the disposal of used filters.
Both agreed with a theme followed by nearly all of the respondents, that having proper fuel quality and oil quality is central to the overall reliability of the operating vehicles and the productivity of the mine. That priority rises higher on the list with new and still-emerging emissions level regulations, such as the need to have extremely filtered fuel that oftentimes also requires filtering down to as low as 2 microns.
“The injection systems necessary to feed the fuel into the engine are operating now at very high pressures in order to get an accurate delivery of the fuel for optimal combustion,” Esplin said.
“In order to achieve such high pressures, the tolerances in the injectors are very fine, therefore any solids in the fuel greater than a few micron in size or water in the fuel can lead to problems with the injectors and cause the equipment to have to be shut down and serviced, which can be expensive and, of course, [result in] significant lost down time.
Alfa Laval also feels that engine lube oil is also critical, with poorly filtered lube oil leading to reliability problems with engines as well as shorter overall engine lifespans.
“Our experience has the engine manufacturers specifying somewhat finer filtration levels; also, servicing of the vehicles in the mines offers significant opportunity to permit dust and dirt into the engine when it is brought in for an oil and filter change,” the two said.
“Anything that can be done to eliminate servicing can help prolong engine life by reducing the risk of dirt entering the engine,” adding that equipment availability improvements also have a hand in the equation.
With the growing popularity of automatic self-cleaning lube oil filters because of their capability to eliminate changing filters until engine overhaul and, therefore, keeping the full flow oil system essentially sealed from outside factors, the company has been combining automatic filters with centrifuges, like with its Eliminator filter. This not only eliminates servicing of the filters, but also highly polishes the oil, extending the lube oil life and further offering savings to the mine and the environment.
While the company has been focusing R&D on emissions and finer filtration — mines have been left in the precarious position of having extreme, tight regulations for emissions but a non-regulated fuel sector — the men said they understand mine managers’ challenges to ensure clean fuel and consistent quality, something that’s not always possible for every operation, particularly outside of the U.S.
“In many locations, it is possible to obtain certain quality levels of fuel in a consistent manner but there are many places in the world as well where the quality of the fuel delivered varies considerably each time and the quality can be quite poor. This means the mine site has to have a robust and adaptable fuel filtration and cleaning process in order to be able to finally deliver fuel to the engine that is at the quality level the injector systems manufacturers have stipulated,” Navarro said.
“Therefore, I could see an opportunity for someone to step into these areas offering fuel at a consistently high cleanliness level, or I see mines adopting more marine-based technologies such as centrifugal separators and automatic filters in the fuel supply stream.”
Alfa Laval has also been partnering with the industry to develop technologies to keep mines’ equipment up and producing, extending service intervals or eliminating them and reducing risk by removing the need to change filters. All of these aspects help with operators’ cost-cutting initiatives and make for a smoother, easier time for those normally tasked with the work.
“For instance, the Alfa Laval Eliminator lube oil filter is an automatic, self-cleaning filter that doesn’t require the filter section to be opened except at engine overhaul, say 20,000-30,000 hours depending upon the engine, and the backflush loop only requires a quick servicing every 1,500-2,000 hours (typically), versus the 500 hours normally associated cartridge filter change intervals,” Esplin said.
“At the same time, Eliminator filter highly cleans the oil, so mines often have been able to double the life of their lube oil prior to changing it. This means greater uptime for the mine…less servicing as well as greater reliability.”
Procurement and Storage
Sendy Soeriaatmadja, global mining sector manager for Shell Commercial Fuels and Lubricants, examined two often-overlooked areas of the fuels and lubricants sector, procurement and storage.
“Contamination control is very important,” he said. “Shell provides a service that can help a customer find and establish the best storage and handling procedures and vendor managed inventory.”
Comparing what’s available today in the lubricants sector versus those products on the market two or three decades ago, Soeriaatmadja said that lines have advanced to keep modern engines running optimally, and R&D efforts have focused on keeping that momentum moving.
“Nowadays customers look for longer oil drain intervals, extended equipment life and increased energy efficiency,” he said. “Shell is aware of its customers’ needs and takes into consideration their feedback when developing lubricants.”
Shell’s current product line includes Rimula heavy-duty diesel engine oils; Shell Omala gear oils; Shell Spirax range of axle, gear and transmission oils; Shell Gadus greases; and Shell Tellus hydraulic fluids.
The company also offers services such as Shell LubeAdvisor, which advises on the best oils to use to improve efficiency and reduce operating costs; Shell LubeAnalyst, which helps sites identify potential failures before they are critical; Shell LubeCoach, a training program to help deliver better performance; and Shell LubeMatch, a free online service that aids in selecting the best vehicle and equipment lubricants.
Shell also has a Shell LubeVideoCheck service, which involves a fiber-optic tool for the inspection of an engine’s internal components, saving the time, manpower and money involved in dismantling it.
Finally, one of the most popular services is Shell LubeExpert, a technical consultation that is available to industrial customers who want a higher level of technical assistance for speciality applications, product support and inspection infrastructure. As part of this service, a team of experienced professionals from Shell works closely with a customer utilizing the unique combination of lubrication products, condition monitoring equipment and techniques that demonstrate tangible cost-efficiency benefits to the customer.
“Mineral-base oils are complex mixtures of naturally occurring hydrocarbons and may contain impurities. For some mineral oils, the lighter, volatile elements can evaporate from hot surfaces, leaving deposits in vulnerable areas like piston-ring zones and leaving the oil too thick to flow to where it is needed.
“In comparison, synthetic lubricants are made from base oils, which contain compounds that were not in the original crude oil, but were ‘synthesized,’ and additives are mixed with the synthetic base oil to improve performance.
“Depending on the product used, additives can account for between 1% and 30% of the lubricant and achieving the right blend is what sets a quality lubricant apart from its competitors.
“As such, additives can be mixed with synthetic base oil to improve its performance, and when working in tandem can keep a machine’s components and moving parts clean and free from deposits, and thus in the best possible condition.
“Regardless of which type is used, applications and refreshment of lubricants and greases are vitally important for all operations, albeit with some variations for different countries and operational conditions.
As a general rule, Shell recommends operators and mining managers focus on OEM specifications when selecting the right lubricant for mining machinery for the best protection of engines, drivelines and other moving parts.
ExxonMobil Celebrates its 100th Anniversary
One long-trusted team in the off-road sector, and mining in particular, has been ExxonMobil’s Equipment Builder Group. This team of technical experts and engineers known for its work with leading original equipment manufacturers (OEMs) to help optimize industrial machinery recently celebrated its 100th anniversary.
Established in 1914, ExxonMobil now works with OEMs in more than 150 countries across the word. The hard work has been thanks to its group of technical experts and engineers.
“These relationships have enabled ExxonMobil to push the boundaries in regards to lubrication formulation and performance,” the company said.
“For example, next-generation products such as Mobil SHC Gear oil have the potential to help industrial organizations secure tangible benefits, such as outstanding protection of gears and bearings as well as extended oil life even under extreme conditions. The new gearbox oil range can also offer the potential to improve the energy efficiency of mining equipment, with some tests recording energy savings up to 3.6% [versus conventional reference oils of the same viscosity grade in gear applications].”
Rainer Lange, Mobil SHC brand advisor for Europe, Africa and the Middle East at ExxonMobil Fuels and Lubricants, noted that its focus today is largely the same: helping the leading mining OEMs develop new equipment that can help to improve their customer’s operations, and using innovation-led relationships with equipment builders worldwide to develop lubricants to help optimize today and tomorrow.
Enter Mobil SHC, which has been part of its effort to secure an extensive range of OEM approvals and recommendations for high performance products.
According to Lange, the Mobil SHC synthetic lubricant line is approved for use in more than 10,000 applications and has preferential endorsements from more than 2,500 equipment builders. The Mobil SHC 600 series of oils alone are approved for use in 1,800 applications.
Additionally, to further help mining companies determine the right oil or grease for their machinery, ExxonMobil has developed Looble — an online Mobil-branded industrial lubricant product selector.
Getting a Grip on Dust with Quaker
Dust suppression is a continuous and costly activity for mining operations, and it limits operational efficiency and impairs visibility increasing the risk of accidents. High dust levels can impact worker health and safety from air pollution and flammability, and negatively affects the environment through erosion, soil loss and excess water consumption.
Lubrication producer Quaker recently heard from a leading coal producer and marketer in the eastern U.S.; the company was getting dust readings on their wall, continuous miners and belt head that reached levels of 1.65 mg/m3. These dust levels were so high, it was causing scum to accumulate in the mine water system and was also causing hosing systems to clog.
Quaker Chemical approached the coal producer about adding the DUSTGRIP water-based dust suppressants to their operations to help eliminate water and hosing system problems while also reducing the amount of dust being measured on their wall, continuous miners and belt heads.
“The coal producer made the decision to add DUSTGRIP TURBO on four of their continuous miner super sections and longwall section,” the company said, noting that the product has been formulated to lower water surface tension, allowing it to penetrate and effectively knock down dust particles.
Since the addition of the dust suppressant, according to testimonials, respirable coal dust levels have been reduced 42% from 1.65 mg/m3 to 0.95 mg/m3. Also, the water lines going to the continuous miner have stayed clean and staff are cleaning out and changing the water sprays on the continuous miner less often.
The operator also reported back to Quaker that it is now using DUSTGRIP 007 dust suppressants on its roadways, and is witnessing a reduction in the amount of respirable dust generated. DUSTGRIP 007 suppresses fugitive dust emissions in areas such as haul/unpaved roads, ore and mineral stockpiles, construction sites, quarries, and other areas where dust may be a problem.