Minergy’s Vitrification Technology Center (VTC) in Winneconne, Wis., U.S.A., operated for 7 years commencing 2000. It was developed as an R&D facility and to prove the Minergy technology using a wide variety of waste streams. The VTC housed several Minergy vitrification technologies and was the location of the Lower Fox River pilot melt. The VTC was home to Minergy’s GlassPack Demonstration Unit, a commercial-scale system to fully demonstrate Minergy’s smaller-scale vitrification technology.
The GlassPack Demonstration Unit was configured to accept a wide variety of material and process conditions. The unit could simulate the Glass Furnace Technology without the expense of constructing a custom unit for a limited duration test of a particular material. The GlassPack Demonstration Unit was placed into service in March 2000. The GlassPack Demonstration Unit successfully processed:
- Contaminated river sediments
- Milwaukee Metropolitan Sewerage District (MMSD) Milorganite
- New York, N.Y.
- Pensacola, Fla.
- Ocean County, N.J.
- Mt. Holly, N.J.
- Detroit, Mich.
- Louisville, Ky.
- North Shore Sanitary District (NSSD)
- Manufactured Gas Plant (MGP) remediation waste
- Paper mill sludges
- Renewable Fuels
- Dry Distillers Grain and Solubles (DDGS)
- Corn Stover
- Wheat Midds
- Corn Bran (Pericarp)
Crucible Testing Final PourMineral components of wastes do not have definite melting points, but rather exhibit a viscosity that is dependent on temperature. High temperature viscosity, a measure of a liquid’s ability to flow (measured in poise), is an important property to understand when making glass. At a viscosity above 250 poise, the material is too thick to flow unassisted and should be avoided in a melter. A common metric, T250, is the temperature at which the material’s viscosity is 250 poise. Ideally the T250 should be less than 2,350 degrees fahrenheit in order to keep melter operating temperatures below 2,800 degrees Fahrenheit.
Mineral composition plays a significant role in determining a material’s high temperature viscosity. Minergy verify that the mineral composition of the waste can be manipulated into the preferred operating temperature range. Included in these services are:
- Mineral composition
- Fuel characterization and variability evaluation
- Fluxing recommendations
- T250 confirmation
At the VTC, Minergy performed crucible melts in an oxy-fuel fired crucible furnace. The crucible furnace had 0.23 m3 of internal volume, a heat input rating of 165,000 Btu/hr, and a maximum operating temperature of approximately 2,800 degrees Fahrenheit. Furnace temperatures were measured continuously with two separate type R thermocouples, and intermittently with an optical pyrometer. High temperature viscosity testing was typically performed in 2,000 cc fused silica crucibles. Viscosity will is determined by the resistance to stirring with a 6.5 mm (1/4 inch) diameter alumna oxide rod. Multiple silicone-based viscosity standards ranging from 10 to 250 poise were used as the laboratory reference.
Viscosity was recorded at 20-degree intervals and continued until the material inside the crucible became too viscous to measure.
After the viscosity testing was completed, the material was heated back up and poured off into a quench tank. Glass aggregate produced was evaluated for physical characteristics as was perferred by our glass aggregate customers. Additional analytical testing, to determine beneficial reuse or other physical characteristics, was also provided when necessary.