Developing alternative explosives: blasting without NOx hazard

In Australia, CRCMining is developing cutting-edge blasting solutions to eliminate the serious hazard of post blast nitrogen oxide fumes (NOx) from coal overburden blasting. This will significantly reduce risk of workplace, health, safety and environmental issues. Post blast nitrogen oxide fumes (NOx) from coal overburden blasting appears to be an industry-wide problem that occurs in a variety of geological conditions and with the use of a variety of bulk ammonium nitrate (AN) based explosive products. Nitrogen oxide and nitrogen dioxide are toxic gases and can cause serious health risks to personnel exposed, and can also adversely affect the environment in several ways.

Increased government and media scrutiny of post blast fume generation and risk control has had a direct impact on the industry’s license to operate. However, research and development into mining explosives since the introduction of ammonium nitrate and emulsions has been at a stand-still for more than 60 years, CRCMining says.

A way to replace AN is a step-change which could offer different alternatives and possibilities to mining companies, particularly with regards to procurement and security of supply.

As part of CRCMining’s research roadmap to deliver outcomes that solve industry grand challenges in surface and underground mining, the Centre in partnership with the School of Mechanical and Mining Engineering of the University of Queensland, is developing ground-breaking solutions that could potentially eliminate the NOx hazard.

The current project aims to develop an explosive formulation that will match the rock breakage requirements of soft and saturated ground conditions, and also substitutes the use of AN as the main oxidising agent, which will completely eliminate the potential of NOx fumes.

Project leader Dr Italo Onederra explains, “This is a very exciting project as it focuses on the elimination of the NOx hazard by applying scientific principles rather than procedural methods, which are prone to variability.”

“Preliminary detonation test results recently published at an international conference are very encouraging. If the explosive delivers the expected outcomes, there is no doubt that Australia will be at the forefront of mining explosives’ innovation,” said Onederra.

Future benefits may also include the elimination of the potential risk of AN discharge into groundwater systems. There will also be potential improvements in overall community safety associated with manufacturing and transportation processes. The development process will also incorporate the use of sustainable and renewable fuel sources into the testing program.

ACARP is currently funding the first stage of development of this project, led by Onederra and Miguel Araos. CRCMining is seeking potential mining partners to launch the next stage of the project and secure trial sites.