Modern Quarrying October-November 2016

SUPPLIER SPOTLIGHT

that ANFO dissolves completely when it comes into contact with water.” High levels of wastage of ANFO – the mining sector typically accepts that about 30% of ANFO delivered to a blast site is not consumed in blasting – suggest that it may be a contributor to nitrate levels in water passing through mine workings. Another advantage of emulsions highlighted by the tests was that no oil was released, ensuring that water con- tamination by oil is also prevented; both the nitrate and the fuel phases of the mix- ture are bonded tightly by the emulsifier. “BME emulsions have already contrib- uted to environmental sustainability on mines by incorporating and consuming previously used oil in its emulsion prod- ucts, helping mines to dispose of these liquids safely and cost-effectively,”he says. “The way we have evolved the matrix also ensures that no oil is released when our emulsion comes into contact with water at the stope face.” As mines work to prevent or mitigate environmental damage, pollution or eco- logical degradation, the levels of nitrate in water are usually monitored – as high nitrate levels can render water unsafe for drinking. “By removing the possibility of nitrate leaching from blasting chemicals under- ground, mines can reduce the risk of groundwater contamination as water drains out of working areas,” Albert con- firms. “At the same time, where mines are making efforts to recycle water from underground, lower nitrate levels will enhance the overall quality of recycled water and increase its applications on and off the mine site.” Emulsion explosive is part of a grow- ing range of underground services being innovated by BME, including up-hole blasting technology, vertical pipelines to convey emulsion direct from surface to working levels, mobile chargers and pumps, and control systems to facilitate real-time communication between under- ground operations and surface systems. www.bme.co.za

resistance, which means that the explo- sive material does not dissolve readily in water,” he adds. “This reduces the amount of nitrate leaching to negligible levels.” Tests conducted by BME indicated that, after being immersed in water for a month, its emulsion released only about 0,7% of its nitrate content. “The key factor here is the effective- ness with which the oil in the emulsion – the fuel phase of the mixture – sur- rounds and isolates the small droplets of saturated oxidizer salt, preventing them from dissolving in water,” says Alberts. “On the other hand, our tests confirmed

contamination and allowing optimal recy- cling of water on site. According to BME operations man- ager Neil Alberts, recent international studies suggest that up to 28% of nitrates from traditional ammonium nitrate fuel oil (ANFO) explosive can leach into water draining through underground mine workings during a blasting campaign. “These levels can be reduced to as little as 2,0% by applying best practice, but the long-term solution lies in explosives that do not release nitrates into water sources.” “Among the characteristics of our emulsions range is its excellent water

As the pioneer in cold emulsion explosives in South Africa, BME has evolved this technology to new levels over the past three decades.

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MODERN QUARRYING

October - November 2016