Extruder glass-melter process for vitrification of nuclear and other toxic wastes
First Claim
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1. A continuous method for vitrifying waste material comprising the steps of:
- (a) introducing the waste material and a vitrification constituent selected from the group consisting of glass and glass formers into an extruder;
(b) conveying the waste material and the vitrification constituent through the extruder applying shear rates and pressures sufficiently high to cause melting of the vitrification constituent while maintaining a maximum temperature in the extruder below 1,050°
C., thereby producing a vitrified waste product; and
(c) removing the vitrified waste product from the extruder;
wherein all steps are carried out on a substantially continuous basis.
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Abstract
A toxic waste and glass frit are fed into an extruder having a helical screw. The glass frit, as well as any glassy material and glass-forming component in the waste, are melted in the extruder as the screw transports the waste and the frit through the extruder. The screw further mixes the waste and the frit and homogenizes the resulting mixture. The extruder is designed to generate high shear rates and high internal friction and at least a portion of the heat for melting is produced by such friction. A vitrified mass of the toxic waste is discharged from the extruder. The vitrified mass can be stored as is or can be pelletized and/or encapsulated.
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21 Claims
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1. A continuous method for vitrifying waste material comprising the steps of:
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(a) introducing the waste material and a vitrification constituent selected from the group consisting of glass and glass formers into an extruder; (b) conveying the waste material and the vitrification constituent through the extruder applying shear rates and pressures sufficiently high to cause melting of the vitrification constituent while maintaining a maximum temperature in the extruder below 1,050°
C., thereby producing a vitrified waste product; and(c) removing the vitrified waste product from the extruder; wherein all steps are carried out on a substantially continuous basis. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification