Mining equipment such as excavators, dump trucks, conveyer belts and loaders to name a few, are reliant on a number of lubricants to help them function. Whether it's an engine oil, gear lubricant, hydraulic fluid or grease, one failure can bring the entire machine operation to a halt. In the extreme conditions, low temperatures and rough terrain typical of mining sites in Russia, machine failure is a common problem, with the associated expense of equipment downtime impacting on operator profitability. For every day that unscheduled downtime occurs, operators stand to lose an average of USD $100,000.
The good news is that recent advancements in lubricant technology have seen significant breakthroughs with regards to extending equipment life, oil drain intervals and improving the performance and overall energy efficiency of equipment,** even in machinery operating in extreme conditions.
Protecting Equipment in Arctic Conditions
In addition to the standard challenges facing lubricants operating in mine site equipment, in places such as Russia, lubricants also need to be able to cope with the 'freeze' factor. As temperatures drop, conventional industrial oils typically thicken and lose their 'pumpability' - this is the oil's ability to circulate throughout a piece of equipment by the oil pump.
Cold, thick oil is more difficult to pump, and if it becomes too viscous, it can stop flowing altogether. With limited or no oil travelling through a piece of equipment, critical components are not properly lubricated during start-up and can develop wear as they come into contact with each other. Selecting an oil that can be pumped quickly to lubricate a machine, even in extremely low temperatures, is important to protect applications. In order for an oil to protect equipment operating in these conditions, it must resist excessive thickening under low temperatures and remain fluid for smooth and consistent circulation.
Due to their formulation and resulting properties, advanced synthetic oils provide better equipment lubrication at temperature extremes compared to conventional mineral oils. For example, they contain higher quality base stocks that enhance their performance capabilities even in sub-zero temperatures, enabling them to protect components soon after a piece of equipment is started.
Most conventional mineral oils are paraffin-based and therefore tend to thicken considerably as the wax molecules crystallize in cold temperatures. This extends the time needed to pump oil throughout an application and requires the equipment to work harder. By comparison, high performance synthetic oils contain fewer waxy paraffins. As a result, they remain fluid down to much lower temperatures and continue to provide equipment with superior protection.
Advanced High Performance Synthetic Oils
An example of a synthetic lubricant that can maintain its fluidity, even at temperatures as low as -46°C, is Mobil SHC™ Gear, a high performance heavy duty gear oil. Mobil SHC Gear oils are formulated to deliver a number of performance advantages versus conventional gear oil chemistries. For example, the range's high oxidation resistance enables extended oil life up to six times* compared to standard mineral gear and bearing lubricants, helping to reduced scheduled and unscheduled maintenance. As well as providing superior protection in challenging environments, in statistically validated laboratory tests and field trials, Mobil SHC Gear fluids exhibited energy savings of up to 3.6 percent** compared with conventional oils, demonstrating the savings that can be made when in investing in an advanced, high performance lubricant.
Improving Gear Box Efficiency by 3.6%
One example of a mine site that has benefited from using high performance lubricants such as Mobil SHC Gear, is a mining company based in Minnesota, USA.*** During Minnesota's winter months, ambient temperatures can dip as low as -40°C, which can impact the viscosity of the lubricant and the resulting protection and performance of the equipment.
The mining company operates a conveyor driven by Falk size 44.5 x 15Z2S double reduction gearboxes. These gearboxes, which were previously lubricated with a mineral-based gear oil, are critically important to the customer's operation. As a result, the mining operation was interested in exploring ways to improve the reliability and efficiency of these gearboxes.
To help meet the customer's goals, ExxonMobil engineers recommended the use of Mobil SHC Gear™ 220. Following implementation of this lubricant series, a 3.6 percent increase in gearbox efficiency was recorded, in addition to improved gear and bearing protection. Based on these results, the customer also expects to extend oil drain intervals from five years to 15 years, without compromising the overall performance of the equipment.
Reducing Hydraulic System Shutdowns
Another example of a high performance lubricant that can maintain its fluidity even at extreme low temperatures is Mobil DTE 10 Excel. As well as offering excellent 'start-up' protection, Mobil DTE 10 Excel™ also successfully operates in temperatures as low as -34°C/-29.2°F. The lubricant is proven to demonstrate exceptional oil life and outlasting standard hydraulic oils by up to three times*, whilst maintaining outstanding hydraulic system cleanliness and component protection.
According to a taconite mining operator in Minnesota, United States, Mobil DTE 10 ExcelTM has delivered more than USD $43,000 in annual savings by helping to improve the hydraulic system reliability of a large wheel loader.
The cooling function of the mining operator's large wheel loader often does not function adequately at the extremely low temperatures found in the taconite mining pits, causing the large wheel loader's hydraulic system to shut down. Following the introduction of Mobil DTE 10 ExcelTM, the operator has reported a reduction in cold weather hydraulic system shutdowns by 75 percent, extended oil drain intervals from 2,000 hours to 8,000 hours, and doubled the life of the pumps.***
Maximising Productivity
To fully ensure the reliability of mine site equipment and lower maintenance costs, it is important, as part of routine maintenance, to check the "health" of the lubricant and the equipment itself.
For equipment maintenance professionals who want an effective oil analysis monitoring programme, there is ExxonMobil's proprietary online Signum OilSM Analysis programme.
Signum Oil Analysis offers engineers access and direct control of their lubricant sampling programme. By combining the use of advanced, high performance lubricants and an effective oil and equipment monitoring programme, mine site operators, even in Arctic conditions, have the peace of mind that their equipment is protected and ready to perform.
For more information about how ExxonMobil's range of Mobil-branded lubricants and services can help mining companies operate effectively in challenging environments, visit mobilindustrial.com.
