The evolution from fire setting in the Bronze Age to blasting using electronics in the modern era has yielded significant benefits for the mining industry, says explosives manufacturer and supplier AEL Mining Services group consulting mining engineer Simon Tose.

These benefits include mitigating damage to the environment, improving the safety and enhancing the efficiency of the blast, which, in turn, also improve the output and yield of mining operations, he adds.

Tose, who recently published a paper, ‘From fire setting to electronics – A fun look at the evolution of explosives’, says the main reason for the shift from using dynamite cartridges to on-site chemical energy coupled with electronic blasting is better control over the blast and the environment.

Subsequently, the blasting process is made significantly safer and more efficient and production improves.

“The earlier haphazard methods of blasting not only to presented safety risks mineworkers – who had no control over the air blast, ground vibration, noise or fragmentation of the rock – but was also very damaging to the environment,” explains Tose.

He says electronic or managed shock tube detonation, currently used in surface and underground mining, provides much better control of the blast, as this method enables one to manipulate the timing of the blast and, therefore, to have more control over the air blast, ground vibration, noise and, most importantly, how the rock fragments.”

Another important consideration is that the electronic system and the manipulation of timing enable blasting without undue noise, one hole at a time. Rock vibration is also minimised, which could be detrimental and hazardous, especially when blasting in a city or suburban area where population encroachment is as close as 250 m to the mine site.

Tose says, because mining is inherently a significantly risky operation, AEL, together with the South African explosives industry, is developing ways to make the process safer and more efficient.

These safety risks have also been the main driver in continually developing explosives and improving the blasting processes, which have prompted AEL to implement leading best practices to not only control blasts better, but also determine the most efficient product combinations in doing so.

Meanwhile, Tose notes that the chemicals are mixed into the explosive formula only at the mining site to ensure that, during transportation, the risk of detonation and the scourge of explosives theft are eliminated.

“The methods of transporting chemicals are very similar to those applied when transporting oil and gas. Chemicals are less volatile than the old dynamites, which were particularly hazardous during transportation,” he says.

Tose says AEL, which is a member of JSE-listed AECI group in South Africa, is committed to making even greater strides in making blasting safer.

“One of the big innovations we are working on is the complete elimination of lead in our detonators. Nitrates also have a negative effect on the ground and reducing these elements will, in turn, reduce their impact on the ground.”

AEL is using lead replacements that are not as harmful to the environment and Tose says that while the bulk of AEL’s detonators are lead free, the company is striving to completely eliminate lead from all its detonators over the next year.

He adds that AEL is considering a wireless electronic system in the future, which would eliminate the use of all wires and allow for even more control in the environment where the blast is taking place.

“For South Africa to meet international safety standards, all stakeholders in the industry need to be aware of the progress that is being made and adapt accordingly to new practices to improve their risk profile and reduce inefficiencies,” concludes Tose.