Company Announcement - Conveyor belt slippage, poor traction, inferior wear properties and inadequate water shedding are nightmares which plague plant operators on mines. All of these can cause unplanned downtime with associated cost implications. However, more critically, conveyor belt slippage is potentially dangerous and could even result in catastrophic failure on a plant. In instances where slippage continues, there is an increased danger of fire as well as damage to the carcass and splice, caused when the belt does not grip.
This is according to Mark Jarrett, national sales manager of Multotec Wear Linings, who says that the company’s MultoLag™ pulley lagging functions as a maintenance free wear resistant cover that is applied to pulley shells to improve traction in the case of drive pulleys and provide a polished low friction surface on non-drive pulleys.
MultoLag™ has become a widely accepted solution for mining and industrial operations as a cost effective response to these recurring problems. “This lagging is particularly effective in aggressive conditions, even on bucket elevators or where material is inevitably trapped between the pulley shell and the conveyor belt. It is suitable for wet conditions and other applications where a low coefficient of friction or a high level of traction is required on drive pulleys or where general wear protection of the non-drive pulley is needed,” Jarrett says.
He points out that traditional rubber or epoxy pulley lagging has a much shorter lifespan than that of ceramics. “This can be attributed to the fact that material is removed from both the rubber lagging and the rubber belt bottom cover when belt slippage occurs. In turn, direct bonded ceramic lagging results in a significant extension of the useful pulley life.”
The system uses standard smooth high alumina ceramic tiles for non-drive pulleys and studded tile lagging for drive pulleys. The smooth/polished surface provided by the very hard ceramics on the non-drive pulleys provides minimal friction, less resistance and therefore no wear. Conversely, the studded tiles on the drive pulleys have a high coefficient of friction of 0.78, which means no relative movement between the surface of the ceramic lined drive pulley and the surface of the conveyor belt. What is significant is that without relative movement between surfaces there can be no wear.
Ceramic lined drive pulleys are covered with high density 20 mm x 20 mm x 6 mm ceramic tiles, with 1 mm high round-edged studs on the tile face that create maximum traction, without the associated damage to belts. The 6 mm thick high density smooth ceramic tiles are bonded directly to the pulley’s surface with specially formulated Multotec Hi-Bond epoxy.
“This epoxy allows us to achieve a bond strength at least 70% higher than that of rubber to steel or rubber to ceramic. It also allows for surface flexing, corrosion protection and water dissipation. In the unlikely event that patching is required, local damage can be repaired quickly without removing the surrounding pulley lining,” Jarrett says.
“The reduced maintenance and downtime, together with enhanced safety benefits, have made the MultoLag™ a highly popular choice for leading mining and minerals processing companies at coal terminals, beneficiation plants, cement plants and quarries. For instance, in one particular application the system has been in operation for over five years in comparison to a mere eight months for the original liner,” Jarrett concludes.