Enhancing the sleep-time of hydrogen peroxide-based explosives

This project has focussed on the development of stable mining emulsion-type explosives using H₂O₂. Through the pursuit of an emulsion-type explosive in H₂O₂-based explosives, certain key advances have been exploited to achieve the density stability that was central to this research project. Specifically, superseding contaminate-rich gums used in hydrogels with chemically synthesised, near-inert-to-H₂O₂ emulsifiers, and the replacement of oxygen-saturated expense fuels, such as glycerol, with hydrotreated oxygen-free, hydrogen-saturated refined hydrocarbon fuels.

A unique characteristic of H₂O₂-based explosives is the potential to eliminate Nitrogen Oxide (NOx) fume emissions, and further reduce Carbon monoxide (CO) fumes from blasting. The toxicity of NOx and its impact on licence-to-operate issues have been extensively reported. It can be appreciated that the nitrogenic pollutants from misfires and dislocated blast columns, an increasing environmental issue, can also be eliminated with H₂O₂-based explosives.  ACARP has been proactive in looking for long-term solutions to address these hazards.  Following from the roadmap outlined in the negotiations for this project, the principal objective of this project was to demonstrate the sleep-time of product to 25 days and conduct detonation characterisation tests of this advanced formulation. This principle objective has been achieved.

Instrumented detonation trials were conducted at the Mining3 Blast chamber, Pinjarra Hills, and RUREX testing range.  The detonation trials, conducted over a 12 month period, have characterised the sleep-time formula and summarised in this report are:

• Detonation performance over a variety of densities;
• Detonation performance at surface mine-site blast hole diameter (~240mm);
• 29-day product sleep-time and detonation;
• Prevention of auto-sensitisation over 22 days, and denial of detonation functionality in unsensitised material;
• Theoretical modelling of explosive performance of varying Oxygen Balance (OB) formulations;
• Laboratory density stability tests of numerous formulations;
• Thermal stability tests (UN test Series 3 (c)) of a water-diluted oxidiser formula.

It is appreciated that the sleep-time tests conducted in this project are a technology first and will receive wider reporting in subsequent journal articles and conference presentations.