Painting mining conveyors and chutes: method and systems

On a mine conveyor, paint protects the structure (stringers, trestles, walkways, guards) against corrosion; it does not protect a surface that ore strikes or slides on all day. Those areas need a wear part or a thick abrasion-resistant lining, and painting focuses on the rest with a high-solids system that goes on in few coats during short shutdowns.

Conveyors and chutes are often the most extensive equipment at a mine or concentrator, and among the hardest to maintain: constant dust, moisture, spillage, work at height and shutdown windows measured in hours. This guide is for maintenance managers and shutdown planners in Quebec and Ontario who want a realistic painting program, alongside our mining equipment painting page.

Which conveyor areas should be painted, and which need wear protection?

Separate three families of surfaces before choosing a product: structure exposed to the atmosphere, areas fouled by spillage, and surfaces in direct contact with ore. Each family calls for a different answer.

Painting the inside of an impact chute means repainting it at every shutdown. For those surfaces, rubber lining, wear plates or a thick polyurea coating are compared based on particle size, impact angle and temperature.

Why do abrasion and dust wear paint out so fast?

Because ore fines act as a slow abrasive and hold moisture against the steel. A layer of wet dust on a stringer stays damp long after rain or washdown, and the salts or process reagents it carries speed up corrosion under the film.

• Surface abrasion. Thin topcoats wear through on edges and traffic areas; a thicker, harder film delays primer exposure.
• Trapped moisture. Pockets, bolted connections and flat-lying angles hold mud; that is where rust shows up first.
• Chemical contamination. Some plants use reagents or loaded process water that settle along with the fines.

The service environment is classified under ISO 12944-2, often as C4 or C5 inside wet concentrators, as explained in our article on ISO 12944 paint systems for C3, C4 and C5. Regular removal of build-up is as much a part of the protection system as the paint.

Which paint systems hold up in these conditions?

High-solids systems, applied in two coats or even one heavy coat, suit mine conveyors best. They build the required thickness in fewer passes, which cuts the number of recoat intervals to manage during the shutdown.

• Surface-tolerant high-solids epoxy. Good adhesion on power-tool-cleaned steel, high build per coat, used as a single coat or as a primer and intermediate.
• Polyurethane or polysiloxane topcoat. For outdoor structures exposed to UV, which chalks epoxies.
• Zinc-rich primer. When blast cleaning is possible and the expected protection period justifies it.
• Low-temperature-cure epoxy. For winter shutdowns in unheated galleries, within the data sheet limits; see our article on cold weather epoxy application.

The final choice depends on the preparation actually achievable, the temperature during the shutdown and the expected protection period. These systems are part of our protective coatings for the mining industry.

How do you prepare the surface when full blasting is not possible?

Match preparation to the area: abrasive blasting where containment is possible, power tool cleaning elsewhere, and a system compatible with the grade obtained. An operating conveyor, surrounded by equipment and belts, rarely allows full blasting.

• Pre-cleaning. Water washing and scraping of build-up, then removal of oil and grease to SSPC-SP 1.
• Power tool cleaning. SSPC-SP 3 for touch-ups, SSPC-SP 11 or SP 15 when a profile is required, covered in our article on power tool cleaning SSPC-SP 3, SP 11 and SP 15.
• Localized abrasive blasting. For dismantled sections, heavily corroded areas or runs isolated from production, with abrasive blasting and suitable containment.

Dust control during blasting in an operating plant is covered in our article on blasting in operating plants.

How do you work during short shutdowns?

Split the conveyor into sections and plan each shutdown as a small, complete job: preparation, application, inspection, housekeeping. One finished section is worth more than three started ones.

• Survey and priorities. Condition survey by section, with priority on steel section loss and critical connections.
• Pre-shutdown preparation. Scaffolding, protection for belts and motors, equipment and products on site before lockout.
• Product choice to fit the window. Recoat and return-to-service times compatible with the actual shutdown length and temperature.
• Coordination. One sequence with the mechanical crews changing idlers and belts during the same shutdown, often run through our project management service.

Safety frames everything else: lockout to CSA Z460, work permits, work at height and respiratory protection according to site and provincial rules.

Do you have to choose between wear parts and paint?

No: on a conveyor, you combine both. The wear part protects the surface that is struck or rubbed, and the paint protects the structure that carries it. The common mistake is painting an impact zone in the hope that a thicker film will do, or the reverse, armouring a surface that only suffers corrosion.

A good test: if the paint on an area disappears between two shutdowns while the neighbouring structure stays intact, that area is a wear problem, not a corrosion problem. Record those areas at inspection and treat them with a wear solution at the next shutdown.

How do you inspect the work and get a quote?

Check preparation, ambient conditions and dry film thickness for each section, and record everything in a log by run. That log lets you track the conveyor from one shutdown to the next and plan touch-ups.

A good log also turns painting into a planned maintenance task rather than an emergency. Each shutdown, the crew starts with the runs flagged at the previous inspection, then moves to the next priority on the list. Over time, the conveyor reaches a steady state where touch-ups replace major repainting, and the wear areas identified along the way are handled by the right solution instead of being repainted again and again.

Our crews and qualified subcontractors work from LaSalle at mine sites, including Abitibi-Témiscamingue. Send photos, run lengths, current condition and planned shutdown durations through the quote request: pricing on consultation, reply within 24 business hours.

Frequently asked questions

Can a conveyor be painted without stopping it?

Parts far from moving components can sometimes be done during operation, with protection in place and site approval. Areas near the belt, pulleys and idlers require a shutdown and lockout.

What minimum preparation does a surface-tolerant epoxy accept?

It often accepts SSPC-SP 2 or SP 3 power tool cleaning over tightly adherent rust, according to its data sheet. Protection still lasts longer with a higher grade of preparation.

Should chute interiors be painted?

Generally not, for impact and sliding zones. A wear part or abrasion-resistant lining is a better fit. The outside of the chute is painted like the structure.

Which colour should conveyors be?

Colour follows site standards and safety marking rules, especially for handrails and hazard areas. A light colour also makes visual inspection for rust and cracks easier.