Explosives company BME states that its double-edged emulsion explosives solution allows customers to quickly identify reactive ground and apply the appropriate product when blasting at their mining operations.
“Among the range of cold emulsions we have developed over the past 30 years is a product suitable for use in reactive ground – an emulsion that is not affected by the sulphides encountered under such conditions,” says BME South Africa GM Albie Visser .
He adds that the problem of reactive ground is often encountered when drilling in shale overburden on coal deposits and in the coal seams themselves. Fine sulphides created by drilling can dissolve in the water in the drill-hole, raising its acidity.
This acidic water, Visser points out, can, in turn, react with normal emulsion explosives, causing it to heat up and potentially risk the performance of the blast – perhaps even resulting in unplanned detonation.
Owing to this, BME developed an emulsion that would not react under these conditions, further enhancing the safety of the blast environment.
“Emulsion products already boast a safety advantage, as they are not explosive until sensitised in the drill-hole; up to that point, their status as a 5.1 oxidiser makes them safe to transport and handle,” he explains.
Moreover, to establish whether there is reactive ground on the drill site, Visser says, customers must be able to test the ground conditions. But sending material for testing can be time consuming.
“So, the solution is also a service that saves customers valuable time; we have developed our own in-house ‘tech truck’, which includes mobile laboratory facilities that can be [used] on site for testing of the ground to be blasted,” Visser says.
This allows the BME team to conduct a visual inspection of the site and apply their experience of blasting in a range of different conditions. The possibility of reactive ground can often be indicated by white patches around the drill holes – resulting from the high acidity of water dissolving the sulphide fines.
“If we suspect that the ground may be reactive, the tech-truck can be brought in to conduct laboratory testing on site,” he says.
Results from these tests can indicate where reactive ground may present challenges, avoiding the risk of discovering the problem only after the emulsion has been pumped into the drill holes. This ensures that blast planning schedules are met and production is not delayed by unforeseen blast-related challenges, concludes Visser.