Explosives Inspectorate | Alert | No.107 V 1 | 11 November 2022
Recent instances of corroded electrical components have resulted in a fire on a Mobile Processing Unit (MPU) and a no-flow condition of an ammonium nitrate emulsion (ANE) pump.
Damaged electrical components in the vicinity of ammonium nitrate product were subject to corrosion. Routine maintenance and pre-start inspections failed to identify and replace affected wiring, solenoids, actuators and switches.
In one instance, a wiring harness with damaged insulation on a MPU bin lid actuator energized resulting in a small fire.
In another incident, an internally corroded actuator energized and started a NAPCO™ ANE pump while the mine re-load was unattended.
Critical hazards associated with ammonium nitrate and ANE that affect electrical components include:
Where ANE pumps are inadvertently activated, or where ANE pumps fail to shut down, no-flow events introduce heat into the ammonium nitrate emulsion, generally under confinement. This can lead to thermal decomposition of ammonium nitrate emulsion and an unplanned detonation event.5
Investigations are ongoing and further information may be published as it becomes available. The information in this publication is what is known at the time of writing.
We issue Safety Notices to draw attention to the occurrence of a serious incident, raise awareness of risks, and prompt assessment of your existing controls.
Contact: Haydn Isaac, Principal Inspector of Explosives – Northern Operations , +61 7 3199 8023 email@example.com
Issued by Resources Safety & Health Queensland
All information on this page (Electrical component failure on ammonium nitrate handling and transfer equipment - https://www.rshq.qld.gov.au/safety-notices/explosives/electrical-component-failure-on-ammonium-nitrate-handling-and-transfer-equipment) is correct as of time of printing (9 Dec 2022 6:19 am).