Modern Mining July 2020

POLYMERIC REPAIR COMPOSITES AND COATINGS

Polymeric repair composites in the mining industry The mining industry brings together some of the most destruc- tive forces affecting modern day machinery and equipment. The threats associated with the mining environment can vary, often introducing a combination of abrasion, corrosion, wear, impact and chemical attack. Significantly, the type of damage that can frequently relies on very specific environmental con- ditions and equipment.

Rapid-curing elastomeric materials like Belzona 2311 (SR Elastomer) offer an alternative solu- tion. They can be applied in situ without specialist tools, eliminating the need for hot work. They offer a versatile repair where durability and elasticity, as well as good abrasion and tear resistance, are required. Rapid cure times also ensure that emergency repairs can be carried out, keeping downtime to an absolute minimum. Shafts Shafts are also a common area for damage in the mining industry. Machine and equipment shafts are susceptible to routine damage from the effects of erosion, corrosion and abrasion, as well as mechani- cal damage due to the failure of bearings, which can cause mining process delays and severe downtime. Common practice might be to use welding as a repair method. This hot work required can per- manently damage the shaft. The repair would also require machining, often meaning these methods need to take place in a workshop. This then requires the need for dismantlement, resulting in more downtime. Aside from also entirely replacing the worn shaft, which is very expensive and time-consuming, shafts can easily be rebuilt to recover their original

occur is completely dependent on the type of mine, whether these are afflictions specific to location, or the type of material being excavated.

O ne of the most common problems in the min- ing industry is damaged rubber components and equipment. This type of problem is regu- larly associated with conveyor belts, which can be torn, ripped and split. Primarily, conveyor belts are exposed to excessive wear as a result of the materials they transport and the friction gen- erated from the rough sliding and impact of these hard materials. As part of their design, the equip- ment surfaces are expected to absorb some of the energy this impact, yet jagged and sharp material can still penetrate the material, tearing and splitting the conveyor belt. The most traditional rubber repair technique within the industry is vulcanisation. This comprises heat and pressure being applied to rubber compo- nents, creating a strong chemical bond. While this does offer a long-lasting repair, the process too

Below: Solutions like Belzona 7111 offer the ideal chocking/ shimming solution by simply pouring the material to flow, contour cure around any irregular surfaces. Centre: Rapid-curing elastomeric materials like Belzona 2311 (SR Elastomer) can be applied in situ without specialist tools, eliminating the need for hot work.

32  MODERN MINING  July 2020