Overview

During 2024–2025, there were six premature detonations due to hot or reactive ground in the mining industry. These incidents can lead to serious injuries or death. The mining industry uses ammonium nitrate (NH4NO3) as the main component in bulk explosives, which are used to extract resources from the ground (iron, coal, copper). When NH4NO3 comes into contact with hot ground (over 55 degrees C) or reactive ground (pyrite, FeS2) it can prematurely detonate. 

Modelling COMSOL Multiphysics was used to model these events in 3D and reveal the temperature profile inside a blasthole over time. Additionally, standard isothermal reactive ground tests were used to assess reactive ground behaviour at high temperatures (70 degrees C). However, inconsistent results promoted further investigation into the test’s setup. The test setup was modelled using COMSOL Multiphysics to quantify heat loss and assess the test’s detection sensitivity. 

Accelerating Rate Calorimetry (ARC) was used to reveal the time taken for explosive runaway to occur, the onset temperatures of this runaway, and the stages of runaway. The addition of urea results in significant increases in safety, which will be examined in the presentation.

This event is produced by Joint Chemical Engineering Committee (JCEC).

Light refreshments will be provided at the event, with opportunities to connect and network with peers and fellow attendees.

Speaker

William McCombe, Undergraduate Engineer, Orica

William is a recent graduate from a double degree of chemical engineering and finance at the University of Sydney, where he received the University Medal. He also received the IChemE award for his thesis, which this presentation is based on. Will completed this project at Orica through the USYD MIPPS program, a six-month placement where you undertake industry-relevant research. Will continued work at Orica after this placement to develop academic papers on hot and reactive ground. Next year, he will be working in financial markets and trading in Sydney.

Sarah Baktr, Undergraduate Engineer, Orica

Sarah is a chemical engineering and science student at the University of Sydney. Sarah completed her project at Orica through the USYD MIPPS program in 2026, continuing on with William’s project from 2025.

Time

18:00–19:45 AEDT.

Programme

In-person:

• 18:00 - Registrations open, refreshments served and networking begins
• 18:30 - Webinar and presentation commences
• 19:15 - Q&A session
• 19:30 - Webinar concludes
• 19:45 - Event concludes

Online:

• 18.30 - Webinar and presentation commences
• 19.15 - Q&A session
• 19.30 - Webinar concludes

Price

Price includes GST.

• IChemE and Engineer Australia member: Free
• Non-member: $30.00
• Student and early career researchers: Free

The material presented in this webinar has not been peer-reviewed. Any opinions are the presenters' own and do not necessarily represent those of IChemE or the JCEC New South Wales. The information is given in good faith but without any liability on the part of IChemE.