What percentage of rock dust should be present in the intake?

The optimal percentage of rock dust that should be present in the intake is 80%. This level of rock dust is significant for several reasons. Firstly, it is crucial for reducing the risk of coal dust explosions, as rock dust can absorb heat and prevent the flames from propagating. By maintaining this percentage, mines adhere to safety regulations that aim to protect workers from potentially hazardous conditions. Additionally, having adequate rock dust in the intake helps in maintaining good air quality and mitigates the impact of coal dust emissions in the mine. Therefore, a consistent percentage like 80% is a standard that balances safety effectiveness with practical application in mining operations.