Shared capture system as an effective method to control dust generated from mineral sample preparation machines
Employees working in a mineral processing laboratory frequently used three machines to prepare mineral samples for analyses. The machines are a jaw crusher, used to break large rock into manageable pieces; a rolling mill, used to reduce mineral sample size further; and a disk grinding mill, which reduces mineral samples from pebble size into dust. This process generates considerable amounts of dust, possibly containing silica, which may cause serious illness.
Because of consultation between laboratory, lecturing staff & the area health and safety representative, the three machines were located side by side in the mineral sample preparation room. An exhaust blower was installed into the ceiling of the preparation room and joined to a capture hood by a length of flexible ducting. The exhaust blower, the capture hood and the ducting combine to form an extraction system.
Hierarchy of Controls:
Dust concentrations were measured with a personal sampler while one sample of rock was crushed in each machine (a duration of 15 minutes).
- Pre and post solution air quality monitoring showed an 84% reduction in the amount of respirable dust (from 112mg per cubic metre with system off to 18 mg per cubic metre with system on).
- Utilisation of the shared control system reduced the cost of controlling the mineral dust hazards.