<div style='margin-bottom: 20px;'> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">What is the primary benefit of using angled blast holes in mining operations?</h2> <p style="font-weight: normal; font-size: 1.2rem;">Improved explosive distribution, throw, and digability of the muckpile.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">Why are angled blast holes not commonly used despite their benefits?</h2> <p style="font-weight: normal; font-size: 1.2rem;">Difficulties associated with drilling the blast holes to the required accuracy.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">What is the purpose of stemming in blasting operations?</h2> <p style="font-weight: normal; font-size: 1.2rem;">To retain high-pressure gases within the blast hole to maximize rock fracturing and heave.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">What determines the mass of explosives required in rock blasting operations?</h2> <p style="font-weight: normal; font-size: 1.2rem;">The distance between the charge and the free face, the number of free faces around the charge, and the geometry of the blasting site.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">How does the choice of stemming material affect its effectiveness?</h2> <p style="font-weight: normal; font-size: 1.2rem;">Angular particles of varying sizes help the material lock together, enhancing the stemming's effectiveness.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">What role does geology play in the success of a blasting operation?</h2> <p style="font-weight: normal; font-size: 1.2rem;">Geology significantly influences blasting results due to the physical properties of the rock and geological discontinuities, which can affect the outcome and necessitate adjustments.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">Why is water resistance important in explosives used for blasting?</h2> <p style="font-weight: normal; font-size: 1.2rem;">Water resistance is crucial because the presence of water in blastholes requires explosives that can withstand or displace water to ensure effective detonation.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">What role does stemming play in blasting operations?</h2> <p style="font-weight: normal; font-size: 1.2rem;">Stemming retains the high-pressure gases within the blast hole for as long as possible to maximize rock fracturing and heave.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">What is the primary consideration in designing a blast for surface mining operations?</h2> <p style="font-weight: normal; font-size: 1.2rem;">The primary consideration is the impact of drilling and blasting on downstream operations, beyond just the cost of these activities.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">How do empirical relationships contribute to blast design in surface mining?</h2> <p style="font-weight: normal; font-size: 1.2rem;">Empirical relationships, based on experience and observation, provide very good results for designing surface blasts when used with understanding of their limitations.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">How does the diameter of a blast hole influence the distribution of explosives?</h2> <p style="font-weight: normal; font-size: 1.2rem;">The mass of explosives per meter of blast hole depends on the square of the blast hole diameter and the average in-hole density of the explosive.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">Why are drill chippings considered ineffective as stemming material?</h2> <p style="font-weight: normal; font-size: 1.2rem;">Their finely ground particles do not lock together well.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">Why is drilling accuracy important in blast design?</h2> <p style="font-weight: normal; font-size: 1.2rem;">It reduces deviation of the blast hole, improving the accuracy and effectiveness of the blast.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">How can the effectiveness of stemming be compromised by rock mass characteristics?</h2> <p style="font-weight: normal; font-size: 1.2rem;">Explosive gases may vent around the blast hole in highly weathered rock, making stemming ineffective.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">How does the presence of different rock types within a blast area affect blast design?</h2> <p style="font-weight: normal; font-size: 1.2rem;">Different rock types can lead to uneven fragmentation and require adjustments in blast design to account for varying responses to the explosives.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">What determines the correct length of stemming?</h2> <p style="font-weight: normal; font-size: 1.2rem;">The correct length produces good fragmentation and heave of the muckpile, while avoiding flyrock and airblast or poor fragmentation and capping.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">How does bench height affect safety and operational concerns in mining?</h2> <p style="font-weight: normal; font-size: 1.2rem;">Higher benches can lead to unsafe conditions with high walls and rolling rocks, and can exacerbate problems like blasthole deviation and coarse fragmentation.</p> </div> <div style="margin-bottom: 10px; background-color: #f2f2f2; border-radius: 1rem; padding: 10px 20px;"> <h2 style="font-weight: bold; margin-bottom: 3px; font-size: 1.5rem;">What is the purpose of sub-drill in blasting operations?</h2> <p style="font-weight: normal; font-size: 1.2rem;">To ensure the floor is broken to grade level, providing a flat area for loading out broken rock and preventing the formation of 'toes'.</p> </div> </div>