In the mining and quarrying industries, the efficient use of explosives is crucial for achieving optimal blast results while minimizing costs and environmental impact. One innovative solution that has gained traction in recent years is the use of blasting gas bags, which enable production blasting with significantly reduced amounts of explosives. This technology not only saves on explosive costs but also contributes to reduced vibration, noise, and environmental disruption.

Production Blasting with Less Explosives

By incorporating blasting gas bags into their blasting programs, mining and quarrying companies can save between 15% to 35% of the total explosive load while maintaining excellent dig-ability. This reduction in explosives leads to substantial cost savings, as explosives are often one of the most significant expenses in these industries. Moreover, the use of gas bags allows for a decrease in vibration and noise levels, making the blasting process more environmentally friendly and less disruptive to surrounding areas.

Achieving Optimal Results with Air Decks

When using blasting gas bags, the placement of air decks within the borehole can significantly impact the outcome of the blast. Mid-column air decks typically produce the best results, especially in casting applications. However, top air decks offer cost savings and are easier to implement. By strategically positioning air decks, companies can further enhance the efficiency of their blasting operations.

Implementing a Blasting Program with Gas Bags

To start a blasting program utilizing gas bags, it is recommended to begin by reducing the explosive charge by 15% of the total length of the hole, while maintaining the same stemming height. After conducting the initial blast, the results should be carefully evaluated. If satisfactory, continue to decrease the explosives by 2-1/2% increments until unsatisfactory results are observed. This approach allows for a gradual optimization of the blasting process, ensuring that the best possible results are achieved with the lowest possible explosive load.

Additionally, it may be possible to reduce the stemming height for better top breakage without risking stemming ejection. This further reduces the amount of explosives required and can improve the overall effectiveness of the blast.

Substitute ANFO for Emulsion Blends in Wet Holes

In situations where boreholes contain water, the use of blasting gas bags becomes even more advantageous. If the holes have only a few feet of water, a gas bag can be dropped onto the water to seal off the hole. A small amount of stemming can then be added, and ANFO (ammonium nitrate fuel oil) can be used instead of waterproof explosives. This system can be employed up to 8 times the borehole diameter of water, offering a cost-effective and efficient alternative to waterproof explosives.

For boreholes with more water, a toe charge can be used to raise the water level. Once the water has been displaced, a gas bag can be placed on top of the water, and ANFO can be used for the remainder of the charge. The toe charge should constitute approximately 30% to 40% of the total charge to ensure effective blasting.

In conclusion, the use of blasting gas bags in mining and quarrying operations represents a significant advancement in production blasting technology. By enabling the use of reduced amounts of explosives while maintaining excellent blast results, gas bags contribute to cost savings, environmental protection, and improved operational efficiency. As companies continue to explore and refine their blasting practices, the incorporation of gas bags will undoubtedly play a pivotal role in shaping the future of the mining and quarrying industries.