Seepage Law and Dust Suppression Mechanism of Controllable Slow-Release Ionic Cross-Linked Dust Suppressant in Coal Seam.

Abstract

Coal seam mining generates significant dust, posing serious threats to the safety of mining and the well-being of miners. This study suggests a delayed cross-linking approach to convert the dust suppressant into a gel within the coal seam, introduces a controllable slow-release ionic cross-linking dust suppressant, investigates its seepage behavior, and evaluates its dust suppression effectiveness in a coal seam. The experimental results show that the dust suppressant exhibits low viscosity and high fluidity during injection into the coal seam, facilitating effective infiltration into the seam. By managing the release rate of Ca²⁺ in the slow-release system, the gelation time of the dust suppressant within the coal seam can be controlled efficiently. While reducing the viscosity, increasing injection pressure promotes material seepage in the coal seam. The optimized injection pressure for the dust suppressant is 7 MPa, and its seepage behavior in the coal seam postinjection resembles that of water. The dust suppressant cross-links and reacts to form a macromolecular mesh structure in tiny internal pores and on the coal seam surface, enhancing the water retention and toughness of the coal seam. These combined mechanisms effectively reduce dust production during coal seam mining, achieving a source reduction of dust production.