South African mining explosives supplier BME has applied a special technology that increases productivity and improves safety in coal-mining operations throughout Southern Africa.
BME blasting technology director Tony Rorke says that the company’s combination of technical knowledge and expertise offers a range of explosives solutions to coal-mining operations.
BME’s technology includes an electronic explosives data logging and reporting system, the XploLogger, in which planned and actual blasting information can be stored and compared, which offers a precise and detailed solution to mines where coal is sourced.
The XploLogger also uses BME’s blasting design software, BlastMap, which was specifically developed to design each blast to exact specifications. Rorke explains that each BME truck operator, who is responsible for charging holes in the field, has an XploLogger, which enables the operator to check the design amount of explosives and record the applied quantity for each hole in a specific blast.
By using the XploLogger technology from BME, mines can do graphical outputs and check the quality of drilling and charging when blasting overburden and coal, he says.
BME GM Albie Visser adds that the company’s blasting technology has operational benefits, including the noting of any deviations, and savings on design costs.
He explains that if any deviation in the rock is found on site, it can be followed up and checked to see if it is a trend in that specific area.
In addition, he reiterates the importance of mines finding a balance between how much explosives are used in blasts, and how much mechanical energy is used to move waste rock, especially in the case of coal-mining.
The biggest impact on coal is coal damage. If the planned depth is shorter than the actual depth, overdrilling takes place, and drillers end up drilling into the coal and damaging it unneces- sarily, says Visser.
He adds that it is integral to ensure that drill holes are at the correct depth, since drilling quality is of the utmost importance in coal-mining.
Further, Rorke states that BME’s bulk explosives are especially safe in overburden blasts where the underlying coal is burning, explaining that, especially in the opencast mining of older coal mines, the combination of water and air results in coal starting to burn, making it a safety hazard to blast a hole without the right explosives and application method.
BME has done tests on its products, and has established that its explosives can withstand very high temperatures, especially in the case of burning coal, where temperatures often reach in excess of 1 000 ºC.
Visser adds that BME’s blasting solution not only involves explosive technology, but also the efficiency of its pump trucks that are able to load 800 kg a minute and ensure the fast and safe loading of the explosives.
He adds that BME has had no accident involving the charging of hot holes, and that the company continues to use emulsion explosives instead of ammonium nitrate in hot holes for safety reasons.
BME also offers electronic delay detonators (EDDs) for overburden blasting in coal, which has the benefit of heaving waste rock as far as possible into the void with the help of the detonator’s precision.
Precise EDDs have become the most important technical advance in blasting, and these detonators deliver consistent and improved blasting results. These include better environmental control, increased safety, finer fragmentation, and the management of heave results.
In one of the biggest electronic detonator blasts that have been done to date in Africa, BME used 3 058 detonators to assist the Eikeboom colliery, a blast which consisted of 2 000 holes, constituting about 800 kg of explosives for each hole, says Rorke.
Rorke states that BME’s BlastMap software was used to programme the detonators beforehand, resulting in a safe and high-quality blast.
The electronic detonator business has had a tremendous impact on quarries, specifically in terms of fragmentation. Coal-mining focuses on throwing and moving waste rock as far as possible, and also involves controlling the vibration of the explosion, says Visser.
Better throw results can be achieved by using the precision of EDDs, while coal mines have reported significant gains in overburden casting.
He states that, since EDDs control vibrations efficiently, there are no concerns about the impact of blasts affecting communities surrounding the mines.
Further, Rorke adds that BME developed its emulsion technology in the coal industry, and that the company has applied recycled oil in its explosives products for the last 20 years.
BME uses a very stable emulsion formulation in its explosives, which prevents the breakdown of the emulsion into pollutants, such as nitrate salts and oil. If explosives do break down in the blastholes, the pollutants can be released into the groundwater system, polluting the environment, he says.
Rorke states that BME is also collaborating on safe charging of high-temperature holes with research body Coaltech’s 2020 initiative, which is a collaborative programme to research, develop and implement technologies for the South African coal industry.