OVERVIEW OF MINERGY’S GLASSPACK® VITRIFICATION TECHNOLOGY
Vitrification, defined as a thermal process for converting minerals into glass, is an emerging technology in the area of treating wastewater residuals. Vitrification has a well established track record in other industrial processes especially glass furnaces used in the glass manufacturing industry and slagging furnaces used in coal-fired power generation.
Wastewater treatment residuals, such as paper mill sludge and biosolids, possess characteristics common to both glass manufacturing and power generation and therefore play two important roles in the vitrification process. First, the organic fraction provides the thermal energy required to complete vitrification. These organics are essentially a biomass fuel that is renewable through the cycle of water use and wastewater treatment. Secondly, the mineral fraction (ash, clays, and mineral fillers) melts into a glass aggregate product with multiple beneficial construction and industrial applications. Until recently, commercial vitrification of waste materials has been limited to hazardous waste applications. Commercial scale vitrification of high-volume industrial wastewater treatment residuals emerged in 1998 with Minergy’s Fox Valley Glass Aggregate Plant (FVGAP) located in Neenah, Wisconsin, USA. FVGAP vitrifies paper mill sludge from several local paper mills into a glass aggregate that is sold and used locally. FVGAP vitrifies approximately 350,000 tons of paper mill sludge into approximately 50,000 tons of glass aggregate annually. Significant interest in FVGAP lead Minergy to develop a second generation vitrification technology, GLASSPACK®, applicable for individual on-site processing of biosolids.