Involves the use of backfill to suppress and/or control oxidation in underground coal mines. GEM Projects methodology include proven SWMS, risk assessments and delivery of all site services.  Oxidation control options include:

• Dry fly ash suppression of goaf oxidation via surface borehole/s
• Wet fly ash smothering of known oxidation zone in the goaf via surface borehole/s
• Dry fly ash construction of a roadway seal remotely from surface via borehole/s.

Fly ash has been used as oxidation suppression of underground coal mines at mines including Newstan, Dartbrook, Blakefield, Muswellbrook, Carborough Down and Narrabri. Fly ash is also used preventative application to reduce airflow before oxidation could occur, and some applications were after tube bundle gas collection started showing signs of oxidation. Dry fly ash seals injected from the surface are lower cost than expanding foam seals.