Compositions and methods for converting hazardous waste glass into non-hazardous products

• US 9,827,457 B2
• Filed: 11/13/2013
• Issued: 11/28/2017
• Est. Priority Date: 04/28/2010
• Status: Expired due to Fees

• Current Assignee: Catholic University of America (Catholic University)
• Original Assignee: Catholic University of America (Catholic University)
• Inventors: Gan, Hao, Chaudhuri, Malabika, Dutta, Biprodas, Pegg, Ian L.
• Primary Examiner(s): Snelting, Erin
• Application Number:
  US14/078,723
• Publication Number:
  US 20140073830A1
• Time in Patent Office: 1,476 Days
• Field of Search: 264667
• CPC Class Codes: A62D 3/33 by chemical fixing the harmful substance, e.g. by chelation or complexation
• CPC Class Codes: C03C 1/002 Use of waste materials, e.g. slags
• CPC Class Codes: C03C 14/00 Glass compositions containing a non-glass component, e.g. compositions containing fibres, filaments, whiskers, platelets, or the like, dispersed in a glass matrix devitrified glass ceramics C03C10/00
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3427 Silicates other than clay, e.g. water glass
• CPC Class Codes: C04B 2235/349 Clays, e.g. bentonites, smectites such as montmorillonite, vermiculites or kaolines, e.g. illite, talc or sepiolite
• CPC Class Codes: C04B 2235/36 Glass starting materials for making ceramics, e.g. silica glass
• CPC Class Codes: C04B 2235/604 Pressing at temperatures other than sintering temperatures
• CPC Class Codes: C04B 2235/72 Products characterised by the absence or the low content of specific components, e.g. alkali metal free alumina ceramics
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 2235/9615 Linear firing shrinkage
• CPC Class Codes: C04B 2235/9638 Tolerance; Dimensional accuracy
• CPC Class Codes: C04B 33/13 Compounding ingredients C04B33/36, C04B35/71 take precedence ; pigments for ceramics C09C1/0009
• CPC Class Codes: C04B 33/1325 Hazardous waste other than combustion residues dredging sludge C04B33/1321
• CPC Class Codes: C04B 33/20 for dry-pressing C04B33/13 takes precedence
• CPC Class Codes: C04B 33/30 Drying methods
• CPC Class Codes: C04B 33/34 combined with glazing
• CPC Class Codes: C04B 35/117 Composites
• CPC Class Codes: C04B 35/20 rich in magnesium oxide , e.g. forsterite C04B35/195 takes precedence
• CPC Class Codes: C04B 35/62204 using waste materials or refuse clay-wares containing waste materials C04B33/132
• CPC Class Codes: C04B 35/62695 : Granulation or pelletising devices for shaping artificial aggregates from ceramic mixtures B28B1/004
• CPC Class Codes: C04B 35/63416 : Polyvinylalcohols [PVA]; Polyvinylacetates
• CPC Class Codes: Y02P 40/60 : Production of ceramic materials or ceramic elements, e.g. substitution of clay or shale by alternative raw materials, e.g. ashes

Abstract

The present invention provides compositions and methods for converting hazardous waste glass into safe and usable material. In particular, the present invention provides compositions and methods for producing ceramic products from toxic-metal-containing waste glass, thereby safely encapsulating the metals and other hazardous components within the ceramic products.

Claims

1. A method of producing a ceramic article from hazardous waste glass comprising:

mixing hazardous waste glass with a filler and a non-aqueous binder, wherein the hazardous waste glass comprises barium and lead, and further wherein the filler is 5-15% of the mixture by weight and the hazardous waste glass is 85-95% of the mixture by weight;

pressing the mixture to produce a green article; and

firing said green article to produce a ceramic article, wherein the ceramic article exhibits lead leachate concentrations of less than 5 ppm and exhibits barium leachate concentrations of less than 100 ppm, and wherein the firing comprises heating the green article to a maximum firing temperature between about 650°

C. and 705°

C.

2. The method of claim 1, wherein the hazardous waste glass comprises one or more of the following characteristics:

greater than 1% lead by weight, greater than 5% lead by weight, greater than 20% lead by weight, CRT glass, fluorescent light glass, greater than 1% barium by weight, greater than 5% barium by weight, and greater than 20% barium by weight.

3. The method of claim 2, wherein the filler is at least one of alumina, magnesium silicate, and bentonite.

4. The method of claim 1, wherein the non-aqueous binder is at least one of polyvinyl alcohol and sodium silicate.

5. The method of claim 1, wherein pressing is at least one of dry pressing, placing the mixture under pressure of at least 200 kg/cm², and placing the mixture under pressure of about 400 kg/cm².

6. The method of claim 1, wherein the ceramic article exhibits barium leachate concentrations of less than 10 ppm.

7. The method of claim 1, wherein the filler is 5-7.5% of the mixture by weight.

8. A method of producing a ceramic article from hazardous waste glass comprising:

mixing hazardous waste glass with a filler and a plastic material, wherein the hazardous waste glass comprises barium and lead, and further wherein the hazardous waste glass is 65-75% of the mixture by weight, the filler is 15-20% of the mixture by weight, and the plastic material is 10-15% of the mixture by weight;

mixing the hazardous waste Mass, the filler, and the plastic material mixture with a non-aqueous binder to produce a batch mixture;

pressing the batch mixture to produce a green article;

drying the green article; and

firing the green article to produce a ceramic article, wherein the ceramic article exhibits lead leachate concentrations of less than 5 ppm and exhibits barium leachate concentrations of less than 100 ppm.

9. The method of claim 8, wherein the hazardous waste glass comprises one or more of the following characteristics:

greater than 1% lead by weight, greater than 5% lead by weight, greater than 20% lead by weight, CRT glass, fluorescent light glass, greater than 1% barium by weight, greater than 5% barium by weight, and greater than 20% barium by weight.

10. The method of claim 8, wherein (i) the filler is at least one of alumina, magnesium silicate, and bentonite;

(ii) wherein the plastic material comprises clay; and

(iii) wherein the non-aqueous binder is selected from the group consisting of polyvinyl alcohol and sodium silicate.

11. The method of claim 8, wherein mixing the hazardous waste glass with the filler and the plastic material comprises wet stirring followed by drying.

12. The method of claim 8, wherein pressing is at least one of dry pressing, placing the mixture under pressure of at least 200 kg/cm², and placing the mixture under pressure of about 400 kg/cm².

13. The method of claim 8, wherein the firing comprises heating the green article to a maximum firing temperature between about 650°

C. and 1250°

C.

14. The method of claim 8, further comprising the steps of:

sieving the hazardous waste glass, the filler, and the plastic material mixture through a first mesh, wherein the first mesh comprises a 50-150 mesh; and

sieving the batch mixture through a second mesh, wherein the second mesh comprises a 10-40 mesh.

15. The method of claim 8, wherein the ceramic article exhibits barium leachate concentrations of less than 10 ppm.

16. The method of claim 8, wherein firing comprises heating the green article to a maximum firing temperature between about 900°

C. and 1050°

C.

17. The method of claim 16, wherein the ceramic article has a water absorption percentage of about 0.2% or less.