Modern Mining December 2015

MATERIALS HANDLING

Lagging system reduces costs

C onveyor belt slip- page, poor trac- tion, inferior wear

properties and inad- equate water shedding are nightmares which plague plant operators on mines. All of these can cause unplanned downtime with associ- ated cost implications. However, more criti- cally, conveyor belt slip- page is potentially dan- gerous and could even result in catastrophic failure in a plant. In in- stances 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™ pul- ley lagging functions as a maintenance-free, wear-resistant cover that is applied to pulley shells to improve traction in the case of drive pul- leys 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 condi- tions, 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 ceramic lagging. The MultoLag™ 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 asso- ciated damage to belts. The 6 mm thick high density smooth ceramic tiles are bonded directly to the pulley’s surface with specially formu- lated 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 sur- face 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.  MultoLag™ pulley lagging functions as a mainte- nance-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.

December 2015  MODERN MINING  33