High-alumina ceramic manufacturer and supplier Multotec Wear Linings’ MultoLag direct bond ceramic pulley lagging system, used for drive and nondrive pulley systems, has achieved an operational life span of over 200 months, compared with only eight months for a previous liner, explains Multotec Wear Linings business development manager Noel Mills.
The 6-mm-thick high-density smooth ceramic tiles are bonded directly onto the pulley’s surface with specially formulated Multotec Hi-Bond epoxy. This allows the company to achieve a bond strength at least 70% higher than that of rubber-to-steel or rubber-to-ceramic.
The epoxy 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.
“An attractive feature of the ceramic material is that, although more costly than conventional lagging, it is field proven,” Mills says.
Another advantage of using ceramics for pulleys is that it can reduce belt take-up masses, owing to increased traction on drive pulleys, which, in turn, reduces belt tension, leading to increased belt and pulley life.
MultoLag lagging serves as a maintenance-free wear-resistant cover, which is applied to pulley shells to improve traction in the case of drive pulleys and provide a polished low-friction surface on nondrive pulleys.
Ceramic-lined drive pulleys are covered with high-density 20 mm × 20 mm × 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 high coefficient of friction, about 0.78, of the ‘studded’ tiles on the drive pulleys ensures no movement between the ceramic-lined drive pulley surface and the con- veyor belt surface. It is not possible for wear to occur if there is no movement between surfaces. Conversely, the smooth/polished surface pro- vided by the very hard ceramic on the nondrive pulleys provides minimal friction, less resistance and, therefore, no wear.
“Ceramic pulley lagging would be used in instances where the pulley operates in extremely aggressive conditions. Typically, this would be in 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. This would include bucket elevators or where material cannot be prevented from becoming trapped between the pulley shell and belt,” Mills points out.
Not only does conveyor belt slippage have negative financial implications for process plants and mines, but it is also potentia- lly dangerous. In instances where the 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.
To alleviate these issues, Multotec Wear Linings developed MultoLag. The standard 100 mm × 25 mm × 6 mm smooth high-alumina ceramic tiles are applied to nondrive pulleys, while studded tile lagging is applied to drive pulleys.
“Multotec’s Direct Bonded Ceramic Pulley Lagging is a cost-effective solution, ensuring optimum traction of drive pulleys in wet and slippery conditions. There have been many instances of substantially reduced downtime and an extended lagging life span for mining and minerals processing companies where the product is installed at coal terminals, beneficiation plants, cement plants, power stations and quarries,” Mills concludes.