Field Experience of Processing Paper Mill Sludge in a Slagging Boiler, 1999 Recycling Symposium Proceedings

Jon F. Myers, PhD., Terrence W. Carroll, P.E.

Minergy’s Fox Valley Glass Aggregate Plant, located adjacent to the P.H. Glatfelter Company’s Neenah, Wisconsin mill, is the world’s first installation to process paper mill sludge in a slagging boiler. The plant make a product called glass aggregate from the combustion of sludge from several area paper mills, including P. H. Glatfelter. The plant is sized to process over 1000 wet tons per day of paper mill sludge. In addition to producing a marketable product from the sludge, the plant also provides process steam to P.H. Glatfelter.

The plant has been in service for just over one year. Main process areas include: wet sludge handling; sludge drying and waste water recovery; dry sludge firing; steam production and distribution; glass aggregate processing; and emissions controls. Field experience in these areas has overcome many obstacles, including changing physical properties of wet sludge under high compression loads; Corrosive attack of certain systems associated with unexpected constituents in the incoming wet sludge; dry sludge and flux handling problems created by high humidity; dry sludge firing pneumatic transport line pluggage from debris introduced with wet sludge or from dryer system deposits; furnace slag flowing issues; and fugitive “fines” control, handling, and containment.