Coal processing and transportation require unique lubrication solutions to preserve equipment performance because of the prevalence of fine coal particles (duff) and their corrosive impact on coal-handling machinery. Along with fine particles, heavy loads, shocks and jars are typical of coal operations and lubricants designed to withstand these conditions are essential to ensure maximum efficiency, says Callum Ford, National Marketing Manager at Lubrication Engineers (LE) South Africa.
“At LE South Africa, our work in the coal processing and transportation industry has shown us that it’s critical to use lubricants designed to repel duff and dirt to protect the equipment at all stages across the coal-handling system,” he says. “We have curated a selection of greases that can tolerate the harsh operating environments surrounding coal while continuing to protect equipment and extend the life of heavy-duty machinery.”
Ford says that the products LE South Africa supplies to its coal industry clients work best in conjunction with some key maintenance techniques. These include making sure grease fittings, fill pipes, plugs and gear tooth surfaces are cleaned before a lubricant is applied. Ford also recommends that drums and containers be kept covered when not in use and stored in a clean, closed area, where possible. The ideal solution is a bulk lubrication storage system, which eliminates risk of contamination and reduces the room for operator error.
When it comes to lubrication, correct application is also important. “For example, plain sleeve bearings that are lubricated with grease should be pumped to capacity, or until some of the old grease escapes at the bearing end,” says Ford. “This provides a flushing action and also seals the bearing against foreign matter getting in and causing damage.”
Fully sealed bearings, where grease cannot easily escape, usually require only a small amount of lubricant, applied at infrequent intervals when using premium quality lubricants. “Operating conditions will largely determine how often each part must be serviced, but generally speaking, regular monitoring of the fluid through oil analysis is best, particularly when aiming for a longer or irregular drain interval. Where the lubricant is continuously reused, such as in enclosed gear units, the oil may need to be changed regularly to keep it free from abrasive matter,” says Ford.
LE South Africa’s range of lubricants for coal processing and transportation have been designed to be as long-lasting as possible, even in harsh operating environments. Ford says the company usually recommends a combination of three high-performing lubricants for equipment along the coal-handling chain. The Almatek® General Purpose Lubricant (1233 & 1235) is highly tacky and designed to withstand shock loading, pound-out and water washout in friction and anti-friction bearings, chassis points and other grease-lubricated applications. “This lubricant is a great solution for coal processing because it clings to metal surfaces and won’t wash off or pound out of pins, bushes and bearings,” says Ford.
The Almagard® Vari-Purpose Lubricant (3752, 3751 & 3750) is a long-lasting, water-resistant red grease that runs cool, even in heavy-duty applications. Ford says it is recommended for extended service applications because it is extremely tacky and will not wash off, pound out or melt and run, even in severe conditions. “We have also seen the Monocal™ GP Grease (1499) perform well in coal-related applications,” says Ford. “It is a versatile grease with calcium sulfonate complex thickener that is especially good at protecting equipment that has to withstand heavy loads, heat and / or moisture.”
Whether a client needs a combination of these three lubricants across a plant, or one particular solution for a specific coal-related function, Ford says, it’s important for operations managers to engage with a lubrication specialist who can help them to find the best lubrication solution.