Anti-caking treated rock dust and its effect on downwind respirable dust measurements

Abstract

Rock dust is required to inert potentially explosive coal dust in underground coal mines. But for rock dust to be effective, it must be able to disperse with the coal dust. Traditional rock dust cakes when exposed to moisture becoming nondispersible when subjected to a light blast of air. To prevent this, anti-caking additives can be applied to rock dust and have proven to prevent caking and to allow for dispersion of rock dust. With the addition of an anti-caking treatment, rock dust can become more fluid and dispersible than without it. There are concerns that rock dust could potentially contribute to downwind respirable dust measurements during deployment of a treated rock dust and due to re-entrainment by personnel or vehicle traffic. This paper examines both potential situations. Although some higher measurements are measured downwind, some areas of the mine would benefit from anti-caking treated rock dust application.