Effects of dust generation rate and source speed on dust.
Proceedings of the 3rd Symposium on Respirable Dust in the Mineral Industries, Pittsburgh, Pennsylvania, October 17-19, 1990. Frantz RL, Ramani, RV, eds., Littleton, CO: Society for Mining, Metallurgy, and Exploration, 1990 Oct; :213-221
The major parameters affecting dust flow at a longwall face are dust generation rate, air velocity and quantity distribution at the face, and the characteristics of the dust such as particle size distribution, density etc. Previous studies have identified the longwall shearer as the major source of the airborne dust in the faces. In this study, the effects of dust generation rate and shearer speed on the levels of ambient dust concentration are investigated. A series of experiments were performed under controlled conditions in a full scale simulated longwall face at the Lake Lynn Laboratory mine of U.S. Bureau of Mines using characterized bituminous coal dust. A trickle-duster was moved up and down the longwall face to simulate the shearer. In each experiment, a known amount of dust was dispersed by the trickle-duster into the air and the average dust generation rate was calculated. At the same time, gravimetric respirable and total airborne dust samples were collected and air velocity measurements were made along the face. The experimental conditions, data, and results are presented and discussed in this paper. The airborne dust concentration and air velocity data indicate that the concentration increases and air velocity decreases with distance from headgate for the first half of the face. Towards the tailgate, the air velocity increases with increasing distance but the dust concentration levels off with some variations. The data show that a higher dust generation rate results in higher dust concentration levels. More importantly, the data show that the rate of increase of airborne dust concentration is higher than that of dust generation rate. For the same air velocity distribution and dust generation rate, lower speed of the dust source results in higher airborne dust levels at the face.
Dust-analysis; Dust-particles; Dust-measurement; Dust-velocity; Dust-sampling; Particulate-dust; Airborne-particles; Airborne-dusts; Respirable-dust; Longwall-mining; Mining-industry
Proceedings of the 3rd Symposium on Respirable Dust in the Mineral Industries, Pittsburgh, Pennsylvania, October 17-19, 1990