Mining Contract: Metering and Distribution Improvements to Increase the Effectiveness and Efficiency of Rock Dusters
Rock dust is distributed throughout the mine to inert float coal dust, reducing the risk of a large-scale explosion. While rock dust is the primary mechanism for ensuring that float coal dust does not provide a continued fuel source to a small explosion or fire, it is critical that the rock dust meet very specific criteria in order to be effective. In order for rock dust to effectively inert float coal dust, it must be distributed throughout the entire mine on a routine basis to ensure that layers of float coal dust are not permitted to accumulate on the mine surfaces. Technologies to measure the amount of liberated float coal dust and determine the necessary quantity of rock dust to be dispersed for proper inertion do not exist. Rather, mine operators generally estimate the amount of needed rock dust and then use visual inspection or the NIOSH-developed Coal Dust Explosibility Meter (CDEM) to determine if more rock dust is required.
Contract Status & Impact
This contract is ongoing.
The purpose of this contract with ROHMAC, Inc., is to develop a prototype dust sensing system, using a commercially available dust sensor, that will determine the amount of airborne dust in an underground coal mine entry and send a signal to a rock duster that injects the appropriate amount of rock dust to inert the coal dust where it deposits in the mine. Additionally, various application devices will be developed and tested during this project with the goal of improving the coverage of rock dust on mine surfaces. Specific study points will be monitoring airborne coal dust, rock dust metering and output control, and distribution methods that improve rock dust coverage in a mine entry.
The prototype dust sensing system is currently under construction at the contractor’s site and is undergoing preliminary testing. The next phase is to test the system at an underground coal mine. Field testing will be performed at an underground coal mine in West Virginia to evaluate system performance and the ability to react in a timely manner to sudden changes in the air velocity and quantity of dust in the air stream. This "need-based" system will monitor the amount of airborne float coal dust in the mine entry, upwind of the rock duster, and send a signal to the rock duster so that an appropriate amount of rock dust injected into the air.
This technology could potentially provide mine operators with a fully automated system that will monitor the amount of dust in the mine atmosphere, calculate the amount of rock dust required to inert the coal dust, dispense the required amount of rock dust, and send out an alert when the rock dust level in the system tank requires refilling.