Definition of Burden
Burden is defined as the horizontal distance from the front of the blast hole to the nearest free face of rock. It plays a crucial role in determining how effectively explosive energy is utilized during blasting operations.
Burden and Spacing
Burden is closely related to spacing, which is the distance between adjacent blast holes. Together, these factors influence the distribution of explosive energy throughout the rock mass. Optimal burden and spacing ensure that energy is efficiently directed toward breaking rock, minimizing unused energy and maximizing fragmentation.
Effect of Burden on Fragmentation
The burden significantly affects fragmentation quality. A proper burden allows for effective micro-fracturing of rock, which is essential for achieving desired fragment sizes. If the burden is too large, the explosive energy may not be fully utilized, leading to poor fragmentation and larger, undesirable rock pieces. Conversely, insufficient burden can result in excessive vibration and flyrock, compromising safety and efficiency.
Importance in Explosive Micro Fracturing
During explosive micro-fracturing, the correct burden allows for the generation of finer fragments by enhancing the distribution of shock waves. This micro-fracturing can be vital in operations like quarrying, where the desired outcome is smaller, more manageable rock sizes that require less processing.
Continuous Improvement and Burden Selection
As rock properties change over time due to geological variations, continuous improvement in burden selection is essential. By monitoring and adapting to these changes, operators can optimize blast designs to maintain effective fragmentation.
In summary, understanding the burden distance effect on fragmentation is critical for optimizing blasting operations, ensuring safety, and achieving desired rock sizes. Continuous monitoring and software tools like WipFrag are invaluable in this ongoing process.
