Assessment of hazard due to release of gaseous ammonia from the fly ash-water mixture applied in longwall mine gobs

Purpose
The introduction of flue gas denitrification technologies by selective catalytic reduction (SCR) or selective non-catalytic reduction (SNCR) in coal fired plants resulted in an increase of ammonia content in fly ash. The utilization of fly ash in fire and ventilation prevention of hard coal mines causes the release of ammonia from a fly ash-water mixture. In the applied technology of the ash and water mixture, ammonia in gaseous form is discharged and mixes with the air flowing through the mine airways. In this article, reference is made to the risk assessment of gaseous ammonia in the longwall area during the application of the fly ash-water mixture to the gobs in the U-tube ventilation system.
Methods
The test methods include: ammonia release from ash and water mixtures at various temperatures and in respect to different proportions of water to ash with use of a multigas analyzer with an FTIR detector.
Results
The results of the laboratory tests helped to determine the size of the ammonia stream released from the fly ash-water mixture in respect to different ratios of water to ash.
Practical implications
Laboratory studies allow for ventilation and gaseous analysis to assess the level of ammonia risk, in the mine airways, from exhaust air discharged from the longwall area.
Originality/ value
Based on the literature review, this type of research has not been carried out so far.