Field study demonstrates inordinate respirable dust generation during continuous mining in rock versus coal strata

Area of Science:

• Mining Engineering
• Occupational Health and Safety
• Environmental Science

Background:

• Continuous miner (CM) machines are essential for modern coal production.
• CMs can generate significant respirable dust, posing safety and health risks.
• Rock strata cutting typically yields more respirable dust than coal cutting, with silica as a key hazard.

Purpose of the Study:

• To quantify respirable dust generation from CM cutting in coal versus rock strata.
• To evaluate the effectiveness of CM dust control methods (scrubbers, water sprays) on different strata.
• To analyze the particle size and mineralogy of dust generated during CM operations.

Main Methods:

• Conducted in-mine field study with respirable dust sampling in active CM operations.
• Compared dust concentrations and particle characteristics during coal-only (bottom) and rock-only (top) cutting.
• Assessed the impact of CM scrubber systems and water spray variations on dust levels.

Main Results:

• CM cutting in rock strata produced 2.1-26 times higher respirable dust concentrations than cutting coal.
• Rock cutting generated somewhat finer dust particles compared to coal cutting.
• CM scrubbers generally reduced respirable dust, while increased water spray pressure showed some benefit when cutting rock.

Conclusions:

• Cutting rock strata with CMs significantly increases respirable dust exposure.
• CM scrubber systems are effective in reducing dust regardless of the targeted strata.
• Targeted water spray enhancements may offer additional dust control benefits when cutting roof rock.