Auxiliary fan rate in stone dust plans is what per operating hour?

• A. 10 kg
• B. 20 kg
• C. 30 kg
• D. 40 kg

Answer: (C)

Stone dusting plans specify how much stone dust an auxiliary fan can deliver each hour to keep a protective coating on coal dust. Thirty kilograms per operating hour is chosen because it strikes a practical balance: it provides enough dust to achieve effective surface coverage along roadways and faces without being excessive. If the rate were much lower, such as ten or twenty kilograms per hour, coverage would be insufficient in many areas, reducing the protective effect. If it were higher, like forty kilograms per hour, it would waste material and could introduce handling or operational inefficiencies. In many NSW plans, 30 kg per hour is the standard that aligns with typical equipment capability and dusting requirements.