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The mining sector’s growing shift toward precision technologies is delivering measurable results, with advanced blast control now central to safety compliance, regulatory confidence and operational efficiency. That shift was evident at a major opencast coal mine in Mpumalanga, where elevated airblast levels had triggered a Section 54 stoppage before new blasting systems and improved engineering restored compliance and reduced costs.
According to BME’s Jacques Botha, High-Tech Specialist for Africa Operations at Omnia Holdings company, the mine had struggled with production blasts that frequently exceeded the 125 dB airblast limit. Historic data showed that pre-split and coal blasts also contributed to the problem, though production blocks were the most significant source. The mine, which extracts about 50 000 tonnes of export coal a month, had been initiating blasts using shock tube systems with inter-hole delays of 17 milliseconds and inter-row delays of up to 84 milliseconds. This design made true single-hole firing difficult and pyrotechnic scatter often caused overlapping detonation waves, increasing the charge mass per delay and escalating airblast effects.
To restore control, BME introduced its AXXIS™ Titanium electronic initiation system, enabling precise timing that eliminated shock wave overlaps and significantly lowered both airblast and vibration levels. The system also allowed presplit blasts to be executed without detonating cord, reducing noise at the source, while firing holes in controlled clusters to manage charge mass per delay.
Investigations revealed that the use of drill cuttings as stemming material was a major contributor to excessive airblast. Stemming lengths were therefore redesigned using the Scaled Depth of Burial guideline. Stemming was increased to 3 metres to maintain energy confinement, while graded aggregate was introduced to replace drill cuttings in production holes. An air deck of 0.5 metres was added to promote fragmentation and reduce oversize material, particularly in the collar zone. Pre-split and coal blasts retained drill cuttings but incorporated stemming plugs to enhance control.
The mine also used the opportunity to review its blasting geometry. By extending its original 4 m by 4 m pattern to 4.5 m by 4.5 m, explosives consumption was reduced without compromising fragmentation. On a 150 m by 35 m block, more than R590 000 was saved, and drilling efficiency improved by 21% due to fewer required holes. The revised layout also created opportunities to extend blasts and expose coal more quickly, supporting production continuity. These combined interventions resulted in an 83% reduction in overall airblast levels, bringing the mine back within regulatory limits and preventing further operational disruption. Botha noted that the success highlighted the growing link between regulatory compliance, cost control and the adoption of modern blasting systems.
“By empowering our customer with optimised solutions, we support and partner to ensure safety standards are maintained and operations continue efficiently,” concluded Botha. The Mpumalanga project underscores how new blasting technologies can reshape operational outcomes, demonstrating tangible value as the industry accelerates toward safer, more controlled and more sustainable mining practices.
