Crushing, Screening, Conveying and Processing Plant
The main hazards
Processing plant brings entanglement, nip points, falling material, noise, dust and stored energy. Guards must be in place on all drives, belts, pulleys and nip points; interlocks must prevent access while the plant can move. Conveyors are a classic killer: entrapment at head and tail drums, and material falling from height.
Blockages and clearing
Blockages are cleared only after isolation, lock-off and proving dead. Never kick, prod or reach into a running machine; never stand on a conveyor or climb on a hopper to break a bridge. Hoppers and silos are confined spaces - bridging and build-up can collapse suddenly, engulfing a person.
Conveyor rules
- Never cross a conveyor except at a designated crossing.
- Emergency stop pull-cords must be accessible along the route and tested.
- Do not ride on conveyors, and do not remove guards to "watch the belt".
- Report tracking faults, spillage and damaged idlers.
Dust and noise
Processing is a major dust source: use enclosures, water sprays, extraction and, where needed, respiratory protection. Noise from crushers and screens requires assessment, signage and hearing protection zones.
Worked example
A jaw crusher is bridged. The correct response: stop feed, isolate and lock off, prove dead, block moving parts, then clear from a safe position using proper tools, under permit if entry is involved. Prodding from above while running is a fatal error.