Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/594078
AGGREGATES MANAGER Voices of Experience Frank Sames Bob Archibald t t A s corporate manager of blaster development for Austin Powder Co., Frank Sames admits that he is biased toward the pros of working with a contract driller and blaster. "As suppliers, our experience in different environments is more diverse," he says. "If you are working as a driller or blaster in-house, you experience a similar (almost the same) environment with every blast. It's possible to become complacent if you don't challenge the status quo on a blast and adjust at the first sign of trouble." He adds that it is a long-time disagreement in blasting whether the "same environ- ment" argument is an advantage or a disadvantage. Sames says that, regardless of whether the work is handled in house or by contract, the technology available today offers a distinct advantage for blast designers, drillers, and blasters. "For instance, it once was a real chal- lenge to accurately measure the burden of every blasthole along the front row of the blast (due to the irregularity of the face)," he says. "Today, with the use of two-dimensional and three-dimensional profiling, it is not so much of a challenge." Face profiling systems in 2D are good for simple faces, allowing the blast designer to determine a perpendicular cross section of the face at each blasthole location. He can then adjust the hole accordingly to the correct distance from the face. More irregular blast faces may require the use of a 3D laser or 3D photogrammetry profiling system to determine the burden in relation to each blasthole. A 3D laser will place points on the face and generate a 3D mesh drawing of the blast face. A 3D photogrammetry system will use digital pictures of the blast face to create a 3D digital image of the blast face. Both types of profiling also help the blaster to more accurately load the hole for the shot. "Along with laser profiling and photogrammetry, there are flyrock models we can use to determine the proba- bility of flyrock and where it might go," Sames says. "It is a decision-making tool for many purposes, including clearing the blast area of personnel." "B lasting is a subject that is near and dear to my heart; I love the blasting aspect of the industry," says Bob Ar- chibald, president of Archibald Consulting Group. He explains that, while the elimination of flyrock in aggregates blasting is a worthy goal from a safety standpoint, perfecting the blasting process can reap numerous benefits. "For example, one quarry I managed near Chicago was having a fines problem off of the primary. We brought in a techni- cal guy from Austin Powder who looked at our blasting, and, based on his recommendations, we changed how we did our surface blasting," Archibald says. "After analysis, we were astonished at the improved fragmentation we had in our muck pile and resulting plant processing costs — all from careful design and monitoring of the blast." Archibald says he feels that, if all producers would analyze their blasting programs similarly, there would be a large re- duction of fines issues in the quarry business. "If you fine-tune your blasting for better product, you will, by default, reduce your flyrock," he says, "and vice versa." If he had to cite the number-one best blasting practice for safety and quality, Archibald says he feels there needs to be open, regular, and thorough communication between the driller and the blaster – including proper documentation and dialog. "The blaster needs to know what geology and irregularities the driller encountered. Based on that, he can plan for proper stemming and timing," Archibald notes. "If the driller does his job correctly, the blaster has a better chance of a safe and effective blast." He adds that, in the case of contracted drilling and blasting, this communication needs to also include the producer, who should monitor all logs carefully. Although the dilemma of whether to contract or to bring blasting in-house will undoubtedly endure, Archibald has a final thought on blasting contractors. "If we bring in quotes for drilling and blasting, we're all guilty of looking at the lowest cost- per-ton," he says. "But we also have to consider that safety and cost go hand-in-hand. The best contractors, with a rigid safety protocol, will ultimately give you the lowest overall cost-per-ton."