NETL conducts a wide variety of in-house research within its Office of Science and Technology. Research pertaining to IEP - Coal Utilization By-Products (CUB) is conducted within the By-Product Utilization Team of the Environmental Science and Technology Division

The objective of the By-Product Utilization Team is to investigate the environmental implications of reusing CUB. Bottom and fly ash can be used in applications including cement and concrete formulation, mine-land reclamation, and agriculture. The gypsum produced as a by-product of some wet FGD units is currently used in the manufacture of wallboard. The team’s goal is to proactively address environmental concerns that arise as a result of changes in the nature of the by-product, such as increased LOI in fly ashes from low-NOx burners, and the production of additional or altered by-products from new pollution control technologies.

• The team’s long term leaching protocol, which has been applied to a large selection of conventional Class F ashes, is now being applied to lignite ashes and to the by-products of new technologies such as SCR/SNCR and mercury-capture.  Current work also focuses on the fate of Hg in CUB.
• The team has developed a short-term leaching test that can be used to evaluate the environmental safety of various environment/CUB combinations. Currently, it is being evaluated in an inter-laboratory comparison of batch leaching techniques.
• The team’s work on high Ca residues, including low-rank coal ashes, FGD, wallboard and CUB containing Ca based sorbents is using both fixed-bed and continuously stirred leaching procedures. While the current emphasis is on Hg, the leaching of other metals is also being monitored.
• The team is investigating the presence and leachability of aromatic and polynuclear-aromatic hydrocarbons in CUB and is attempting to determine if current and contemplated pollution control technologies affect the amount of PAH found.
• Past work has also included a field investigation of the effects of using alkaline CUB to control acid mine drainage from surface coal mine spoils at a local airport.
   

Related Papers and Publications:

• Relative Solubility of Cations in Class F Fly Ash, published in Environmental Science & Technology Magazine [PDF-71KB]
• Factors Controlling the Solubility of Mercury Adsorbed on Fly Ash presented during the 2005 World of Coal Ash [PDF-224KB]
• Leaching Methods Applied To The Characterization Of Coal Utilization By-Products presented during the 2005 World of Coal Ash [PDF-130KB]
• Water Quality Changes Related to CUB Bulk Placement at the Rostraver Airport presented during the 2005 World of Coal Ash [PDF-321KB]
• Preferential Acidic, Alkaline and Neutral Solubility of Metallic Elements in Fly Ash, presented during the 2005 World of Coal Ash [PDF-329KB]
• Leaching of CUB Using a CSTX, presented during the 2005 World of Coal Ash [PDF-137KB]
• Release of Ammonia from SCR / SNCR Fly Ashes, presented during the 2005 World of Coal Ash [PDF-37KB]
• Effects Of pH, ORP, And Conductivity On Leaching Of Trace Metals From Fly Ash, presented during the 2005 World of Coal Ash [PDF-158KB]
• Distribution of Mercury in FGD Byproducts, presented during the 2005 World of Coal Ash [PDF-115KB]
• Inter-laboratory Comparison of Leaching Methods, presented during the 2005 World of Coal Ash [PDF-336KB]
• Rapid Batch Characterization of Coal Utilization By-Products, presented during the 2005 World of Coal Ash [PDF-161KB]

Contacts:

• For further information on In-House R&D for Coal Utilization By-Products, contact Dave Wildman and Karl Schroeder.