The wettability of coal and its relevance to the control of dust during coal mining.
J Adhes Sci Technol 1993 Jun; 7(6):649-667
Water sprays are used on longwall mining machines to help control respirable coal dust during underground mining operations. Surfactant reagents added to the sprays, if properly selected, can improve the coal dust wettability and capture efficiency of water droplets. Combining water-soluble polymers with a surfactant can improve dust suppression further by altering the adhesion-cohesion properties of water droplets. The mechanism of coal dust control using a surfactant-polymer reagent is discussed. The Bureau of Mines tested an anionic surfactant-polyethylene oxide polymer water spray additive in the laboratory and in an underground longwall coal-mining operation. The results were encouraging but anomalously high headgate dust concentrations were consistently observed when the surfactant-polymer reagent was injected during the longwall tests. A hypothesis, based on rheological considerations and an adaptation of the Good-Islam liquid bridge model, is suggested to explain the phenomenon. A brief example of the method for correcting the mine dust concentration data for the excess headgate dust is given.
Mining-industry; Underground-mining; Coal-mining; Coal-dust; Dust-control; Dust-control-equipment; Dusts; Longwall-mining; Respirable-dust;
Author Keywords: Dust suppression; coal wettability; adhesion; surfactant; water-soluble polymer; agglomerates; longwall mining
Journal of Adhesion Science Technology