1. What is Stemming at Top of Borehole?

Stemming at Top of Borehole involves preventing soil or fluid influx during drilling operations to maintain stability and prevent explosive gases from escaping. It is a critical safety measure in mining and drilling operations.

2. How Does the Calculator Work?

The calculator uses the stemming formula:

Where:

• \( S \) — Stemming at Top of Borehole (Meter)
• \( B \) — Burden, the distance from the blast hole to the nearest perpendicular freeface (Meter)
• \( OB \) — Overburden, the material that lies above an exploitable area (Meter)

Explanation: The formula calculates the appropriate stemming length based on burden and overburden measurements to ensure proper containment of explosive gases.

3. Importance of Proper Stemming

Details: Proper stemming is crucial for maintaining borehole stability, preventing gas escape, ensuring efficient energy transfer from explosives, and maintaining safety standards in mining operations.

4. Using the Calculator

Tips: Enter burden and overburden values in meters. Both values must be positive numbers greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: Why is stemming important in drilling operations?
A: Stemming prevents explosive gases from escaping, maintains borehole stability, and ensures efficient energy transfer from the explosives to the surrounding material.

Q2: What factors affect stemming requirements?
A: Burden distance, overburden material properties, explosive type, and borehole diameter all influence stemming requirements.

Q3: Can this formula be used for all types of explosives?
A: While the formula provides a general guideline, specific explosive types and geological conditions may require adjustments to the stemming calculation.

Q4: What are the consequences of inadequate stemming?
A: Inadequate stemming can lead to gas escape, reduced blast efficiency, flyrock hazards, and potential damage to surrounding structures.

Q5: How often should stemming calculations be verified?
A: Stemming calculations should be verified whenever there are significant changes in geological conditions, explosive types, or operational parameters.