January 3, 2020
Volume 7 Issue 4
Calcium Sulfonate Greases Gain in Mining
SINGAPORE – Lithium grease thickeners still make up the majority of the global market because of their lower cost, but demand for products made with calcium sulfonate thickeners is expected to grow because of their better performance in industries such as mining, industry insiders said at a conference here.
“Calcium sulfonate, with inherent [excellent] extreme pressure characteristics and superior wet performance, has gained some traction,” Andrew Black, general manager of technology and manufacturing at Harrison Manufacturing, said at the Asian Industrial Lubricants Conference in November. Harrison Manufacturing is an Australian-based toll lubricant and grease manufacturer. “Despite higher initial cost, its sector continues to grow globally.”
Machines used in mining operations, including dump trucks, bulldozers and draglines, are slow-moving with high load-carrying capacity and have to be resistant to shock loads and vibration. The machines work under dusty and hot conditions that may be wet or severely dry environments. Calcium sulfonate greases perform well in such conditions, Black explained.
Using the ASTM standard test method for weld load, which measures the EP performance of lubricating grease, EP-additized lithium complex grease has a weld point of 500 kilogram-force while EP-additized calcium sulfonate complex grease has a weld point of 800 kgf. The higher the weld point, the better the substance performs.
“This is a price-sensitive market with stringent original equipment manufacturer specifications, and there is a trade-off between cost and performance,” he said.
“Lithium and aluminum-based greases will continue to play a key role. There is growth in additized calcium sulfonate complex grease,” Anuj Mistry, product manager for grease in Fuchs Lubricants’ OEM division, told attendees at the conference. “This technology will come and grow as we move forward.”
Black said Lithium thickeners are not about to go away, though. “Lithium and lithium complex [grease] are dominant players in Australia and the region,” Black added. “There has been some resurgence of lithium simple grease.”
He added that lithium is an attractive option because of its cost but that there is still room for improving performance. Experiments with “borate esters have been shown to improve the dropping point while maintaining the superior pumpability of lithium grease,” he explained.
“[There is] potential to match higher grease specification at a lower cost. Cost of lithium greases additized with borate increased 11 percent, while lithium complex cost 40 percent more with longer cycle time,” he added.
Major mining countries in the Asia-Pacific region are Australia, China, India and Indonesia. In emerging markets, Vietnam’s coal, copper and gold mines and Myanmar’s copper, tin, gold and rare earth mines are attracting foreign mining companies.