Building Seals by Pneumatic Stowing in Mine Closure Operations

摘要

The Bureau of Mines, through a cooperative agreement with Duquesne Light Co. of Pennsylvania, field tested a method of using pneumatic stowing of crushed limestone to construct seals in long-abandoned mine openings that were part of an active mine closed shortly before sealing. A total of 13 openings at 11 sites were backfilled. In pneumatic stowing, material is conveyed through a pipeline and into the mine opening under low air pressure. The stowing equipment consists of a power supply, a blower, a feeder to inject material into the pipeline, and nozzle for directing the placement. Material is ejected from the nozzle at high velocity, creating a high-compaction fill upon impact.