Owing to ongoing research and development on emulsion explosives for the mining industry, emulsion explosives company BME now has the ability to customise emulsion to suit the needs of each quarry or mine.

“Emulsions have made blasting safer because they are not classified as an 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 – and simplifies logistics by not requiring the special licensing, permissions and facilities required by traditional explosives,” says BME South Africa and Namibia GM Albie Visser.

The long shelf life of the BME emulsions makes them easier to store – allowing quarries and mines to reduce supply chain risk where distances and accessibility make transportation difficult; and they do not require dedicated magazine facilities, saving on cost and administration.

Visser indicates that many customers have applications in which the emulsion needs to be pumped a number of times before it is fed into blast holes. He notes that this does not pose a challenge for the company, as the double-salt formulation of the emulsion allows BME to successfully repump its emulsion multiple times, with no degrading impact on the product.

Emulsions also have a higher velocity of detonation than ammonium nitrate fuel oil (Anfo), which improves fragmentation for quarries and hard rock mines. In underground applications – where pumpable emulsions have begun offering exciting opportunities – it reduces damage to side walls and hanging walls, as there is less gas energy and more shock energy in the product.

“With our experience of developing, manu- facturing and testing emulsions in the field, our emulsions have evolved to offer value-adding bene- fits. In fact, we can now engineer a site-specific emulsion for a customer’s particular conditions and blast outcomes.”
He highlights that the com- bined importance of high-quality raw materials and ongoing investment in research and devel- opment is key to the company’s product success.
The range of BME emulsions allows customers in quarrying and opencast and underground mining to take advantage of its benefits. In the opencast environment – BME’s traditional market – HEF emulsion is used for small-diameter surface drilling. Heavy Amfos, which are emulsions blended with ammonium nitrates, are supplied by BME for larger-sized drill holes.
BME’s research has also pioneered the increased percentage application of used oil as a fuel agent for the emulsions, reducing mines’ environmental impact while maintaining the highest quality of ammonium nitrate- and calcium nitrate-based emulsion product.

BME has also made progress in helping customers address the challenges presented by reactive ground by developing a specialised emulsion for use in these conditions. Reactive ground is commonly encountered when drilling in the shale overburden on coal deposits, in the coal seams themselves and in sulphide orebodies.

“Here, fine sulphides created by drilling can dis- solve in water, which, in turn, reacts with normal emulsion and potentially risks the performance of the blast or, in the worst case, [results in the] pre- mature reaction of the explosives. “By contrast, BME's product does not react, ensuring problem-free blasting in reactive ground,” he concludes.