Glass Furnace Technology (GFT) Demonstration at the Hazen Research Center in Golden, Colorado and the Minergy GlassPack Test Center in Winneconne, Wisconsin

Site Name:

Hazen Research Center and Minergy GlassPack Test Center


Golden, CO and Winneconne, WI

Period of

January 2001 (dryer evaluation); August 2001 (melter evaluation)


Field Demonstration

Ex Situ Glass Furnace Technology (GFT) (Vitrification)
- Demonstration process - two steps: sediments drying (dryer) and dried-sediment vitrification (melter)
- Sediment dryer - Holoflite® dryer that was a small batch, bench-scale unit with a capacity of 14 lb/hr of dewatered sediment (45-55% by weight); portions of the sediment were dried and mixed with the dredged and dewatered sediment to create better flow characteristics of the feed material; unit was 30-in long with two hollow, oil-filled augers; oil heated to about 180°C; dried sediment had a moisture content of <10%; steam from dryer condensed and collected;
- Melter - pilot-scale glass furnace designed to simulate full-scale production - 8 split-stream, oxygen-fuel burners; fired with oxygen and natural gas to control nitrogen-related and particulate emissions; refractory brick; charger was a standard screw feeder, retrofitted with a small screw barrel and flights for the demonstration
- Melter characteristics - melter area was 10 ft2 ; length/width aspect ratio of 2:1; melting rate - 5.4ft2/ton; dwell time - 6 hrs; gas usage - 1.7 MM Btu/hr; oxygen usage - 35 cubic ft/hr; output - 2 tons/day
- Process controls - thermocouple signals to maintain constant temperature and automatically adjust gas and oxygen in each zone

Cleanup Authority:
EPA SITE Program

Ms. Marta K. Richards
EPA SITE Project Manager
National Risk Management Research Laboratory
26 West Martin Luther King Drive
Cincinnati, OH
Telephone: (513) 569-7692
Fax: (513) 569-7676

Mr. Terry Carroll and Mr. Tom Baudhuin
Minergy Corporation
1512 S. Commercial St., P.O. Box 375
Neenah, WI 54957
Telephone: (920) 727-1411
Fax: (920) 727-1418

Polychlorinated Biphenyls (PCBs), Heavy Metals, Dioxins/Furans
- Total PCB concentration in sediments in the 20 to 30 ppm range
- Other contaminants included mercury, dioxins and furans

Waste Source:
Contaminated river sediment dredged from the Lower Fox River

Type/Quantity of Media Treated:
- Dredged sediments - dewatered form (45-55% solids by weight)
- The report stated that because GFT is not designed to be used on one particular site, information about site location and hydrogeology are not needed for demonstration purposes

Purpose/Significance of Application:
Demonstration of GFT to treat river sediment contaminated with PCBs, other organics, and metals

Regulatory Requirements/Cleanup Goals:
- Primary objectives of the demonstrations were to determine the treatment efficiency of GFT in treating PCB-contaminated dredged-and-dewatered sediment, and to determine whether GFT glass aggregate product met relevant regulatory criteria for beneficial reuse

- Total PCBs - 99.9995% of total PCBs were removed or destroyed
- Mercury - reduced from concentrations slightly less than 1 ppm to non-detect in the glass aggregate; report stated that if mercury was not removed thermally, it was likely inactivated within the glass matrix
- Dioxins and furans - >99.9995% reduction
- Glass aggregate met the state of Wisconsin requirements for beneficial reuse
- Leach test results of glass aggregate, including Synthetic Precipitate Leaching Procedure (SPLP) - no contaminants detected in leachate

Cost Factors:
- Report includes detailed cost analysis for the technology
- Estimated unit cost for full-scale GFT is $38.72 per ton of dredged-and-dewatered sediment, based on 50% moisture and a 15 year project life expectancy
- Costs may depend on location of treatment facility, amount of moisture in the sediment, and the potential end use of the product

Glass Furnace Technology (GFT), developed by Minergy Corporation, was evaluated by the EPA SITE Program. The demonstration included an evaluation of the drying process at the Hazen Research Facility in Golden Colorado in January 2001 and an evaluation of the melter at Minergy’s GlassPack Test Center in Winneconne, WI in August 2001. The primary objectives of the demonstration were to evaluate the effectiveness of GFT in treating PCB-contaminated sediments that had been dredged and dewatered and to determine if the glass aggregate product met relevant requirements for beneficial reuse. Sediment dredged from the Little Fox River in Green Bay, WI was used for the demonstration; the sediment was dewatered to a moisture content of 50% by weight.

Results of the demonstration showed that GFT removed or destroyed contaminants in the sediment including 99.9995% of the PCBs (measured as total PCBs), >99.9995% of dioxins and furans, and appeared to be capable of reducing mercury concentrations. In addition, the glass aggregate met the Wisconsin Administrative Code Chapter NR 538 Category 2 criteria and qualified for beneficial reuse. Projected full-scale unit costs of GFT are $38.74 per ton of sediment treated (50% moisture), with costs dependent of factors such as location of the treatment facility, sediment moisture content, and potential end use of the product. According to the vendor, GFT is designed to treat contaminated river sediment at any location and can be scaled to accommodate a wide range of sediment projects. The report indicates that possible areas where scale-up economies could be realized include lower energy costs per ton of sediment treated, reduced sampling and analysis requirements once the treatment efficiencies for the technology are established, and the potential to automate some of the processes.