When it comes to drill and blast designs in mining, every design parameter used is crucial to obtain the best result after the blast. The question commonly asked is, where to start?
Rule of thumb, experience, technology, learnings, and previous results are all factors contributing to a successful blast. World Blasting Innovators is a community where professionals come together to improve their design thinking skills to optimize Drill and Blast designs to achieve great results.
The good news is that there are rules of thumb that can be used as a first estimate in the absence of any better data.
✔ Blast hole diameter in mm ≤ 15 x Bench height (BH) in metres
✔ Bench height (BH) in metres ≥ (Blast hole diameter (D) in mm)/15
✔ Burden (B) = (25 to 40) x (D)
✔ Spacing (S) = 1.15 x B (This gives an equilateral pattern)
✔ Subdrill = (3 to 15) x D
✔ Charge length (C) ≥ 20 D
✔ Stemming ≥ 20 x D or (0.7 – 1.2) x B
✔ Stemming material size = D/10 to D/20
Link to World Blasting Innovators community. https://www.worldblastinginnovators.com/