Mine Ventilation & Atmospheric Monitoring Flashcards
7 cards from real CMSP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Mine Ventilation & Atmospheric Monitoring flashcards as text
According to MSHA regulations (30 CFR 75.323), at what methane concentration must all miners be withdrawn from an underground coal mine working section?
Answer: 2.0%
At 2.0% methane, all miners must be withdrawn from the affected area; at 1.0% production stops, and at 1.5% all but those correcting the hazard must withdraw.
What is 'blackdamp' as encountered in underground mining?
Answer: A mixture of carbon dioxide and nitrogen that displaces oxygen
Blackdamp is a mixture primarily of CO2 and N2 that displaces oxygen and can cause asphyxiation; it is heavier than air and tends to accumulate in low areas.
Which instrument is most commonly used to measure air velocity in underground mine airways?
Answer: Vane anemometer
A vane anemometer measures airflow velocity by using rotating vanes; it is the standard tool for ventilation surveys in mine airways.
What is the minimum required oxygen percentage in the atmosphere of an underground metal/nonmetal mine according to MSHA (30 CFR 57.5005)?
Answer: 19.5%
MSHA requires a minimum of 19.5% oxygen in underground mine atmospheres; below this level, the atmosphere is considered oxygen-deficient.
What is the primary function of a main mine fan installed on the surface?
Answer: Circulating air throughout the entire mine to dilute and remove contaminants
The main mine fan creates the pressure differential that drives fresh air through the entire mine ventilation circuit, diluting and removing methane, dust, and other hazardous contaminants.
In mine ventilation terminology, what is 'afterdamp'?
Answer: The toxic gas mixture (including CO and CO2) remaining after a mine explosion or fire
Afterdamp is the toxic mixture of gases—including carbon monoxide, carbon dioxide, and nitrogen—that remains in a mine after an explosion or fire, and is a leading cause of post-explosion fatalities.
A ventilation 'regulator' in an underground mine is used to:
Answer: Reduce airflow in a specific airway to control distribution across the mine
A regulator (typically a door or restricted opening) creates additional resistance in an airway to reduce airflow and redirect it to where it is needed, balancing the ventilation circuit.