In November 2017 a major iron ore port facility in the Pilbara decided to replace the ceramic lagging on a high tension bend pulley – the ceramic lagging had suffered physical damage on one edge that had exposed the pulley shell (Photo#1). With a capacity of around 180 million tonnes/ annum of iron ore the port operates 24/7 year round and so reliability of the conveyor system is critical to achieving the maximum ore through put.
Spare pulleys are held so that in the event that an operational pulley requires replacement this can be done quickly and efficiently at the timing dictated by the mine maintenance personnel. The reason for changing a pulley broadly falls into two categories.
• Change out during a planned maintenance shut
• Emergency change out due to catastrophic pulley failure
Our dedicated teams in Australia and Vietnam working really hard to understand lagging performance, and to engineer solutions that provide the longest possible lagging service life under all conditions.
Catastrophic lagging failure due to debonding occurred within two weeks of installation and operation of the pulley, resulting in a shutdown of production, and necessitated a replacement of the pulley. Within only two weeks of service, this ceramic lagging was already experiencing loss of the ceramic tiles.
Early in 2019 Kledkaew Inter Products Co, Ltd. a rubber lining company based in Bangkok Thailand were approached by a representative from a major power station, with a request for a pulley lagging that would significantly extend the lagging service life beyond the 12 months that was typically being achieved with the rubber lagging currently in use.
Ceramic lagging is chosen for pulleys where a long trouble free service life is required to ensure that the conveyor is operational when required and to avoid unplanned conveyor shutdowns. This is a critical for mining companies where conveyor down time costs run into thousands of dollars per minute.
Correct pulley shell surface preparation is essential for good lagging adhesion. Grit blast to a 50-100 um surface roughness and check by measuring at multiple points across the pulley face and around the pulley circumference.
EL.IN. is an engineering company based in Grevena in northern Greece. For many years EL.IN. has been refurbishing pulleys for the Public Power Corporation (PPC) of Greece. PPC operates seven power stations that are fuelled by Lignite and a number of mines that supply the fuel for these mines. The PPC operations have conveyor systems with over 2,000 pulleys in service with a number of different lagging types in service, including rubber, cold vulcanised ceramic and direct bond ceramic.
The Curragh Coal Mine is an open cut coal mine located near Blackwater in Central Queensland, Australia. The mine supplies high quality, low ash coking coal and has reserves of approximately 90 million tonnes which is amongst the largest in the world. Coal from Curragh is shipped via the Blackwater rail system to the Port of Gladstone for export. Curragh Coal mine is owned by the Coronado Coal Group a US based company.