White Pozzolan Manufactured From Post-Consumer Waste Glass, Products Incorporating the Same and Methods of Manufacturing the Same

Abstract

A clean dry white glass powder useful as a substitute for Portland cement in concrete, in paints, and for other known uses for glass powder produced conventionally can be produced from unsorted post-consumer waste glass, including a substantial fraction of non-glass items, by employing glass pulverizing equipment to reduce waste glass to small fragments, allowing removal of trash, employing a multistep washing process to clean the glass fragments, in the preferred embodiment using aggregate cleaning equipment, drying the fragments, preferably using fluidized bed techniques, and grinding the glass to a desired particle size, preferably using a ball mill, in combination with an air classification step to produce a bright white glass powder of uniform particle size.

1 .- 21 . (canceled) 
     
     
         22 . A white glass powder manufactured by a process, comprising:
 a) supplying a stream of mixed-color post-consumer waste glass containing organic contaminants and items of non-frangible materials;   b) then pulverizing the stream in a manner such that consumer waste glass in the stream is reduced to fragments of average maximum size ⅛ inch or less, while non-frangible items are not reduced to said size;   c) then performing a size-based separation of the reduced glass fragments from the non-frangible items;   d) then washing the reduced glass fragments to separate plastic and paper fragments and organic contaminants therefrom;   e) then drying the washed glass fragments to a moisture content of no more than about 2% by weight;   f) then grinding the dried glass fragments into a white powder having a brightness of at least 77 using the ASTM E 313 standard practice, wherein the grinding is performed in a mill that grinds media having a non-metallic surface against the dried glass fragments;   g) then removing the white glass powder;   h) then returning the remaining particles to said grinding step for grinding with additional dried glass fragments received for grinding from after said drying step; and   i) repeating steps g) and h) for continuous manufacturer of the white glass powder.   
     
     
         23 . A white glass powder according to  claim 22 , wherein:
 said white powder has a brightness of 77 to 80 the ASTM E 313 standard practice.   
     
     
         24 . A white glass powder according to  claim 22 , wherein:
 the mill of said grinding step includes a drum lined with a non-metallic surface that does not impart a non-white discoloration to the powder during grinding.   
     
     
         26 . A white glass powder according to claim  25 , wherein:
 said drum is lined with stone.   
     
     
         27 . A white glass powder according to  claim 24 , wherein:
 said grinding media are balls having a ceramic surface.   
     
     
         28 . A white glass powder according to  claim 27 , wherein:
 said grinding media are solid ceramic.   
     
     
         29 . A white glass powder according to  claim 22 , wherein:
 a classifier coated with a non-metallic material is used for said removing and said returning.   
     
     
         30 . A white glass powder according to  claim 22 , wherein:
 at least 60 percent of said white powder has a size of 325 mesh or smaller.   
     
     
         31 . A white glass powder manufactured from a stream of post-consumer mixed color waste glass containing items of non-frangible materials, said white glass powder made from the process of:
 a) pulverizing the stream in a manner such that consumer waste glass in the stream is reduced to fragments of an average maximum size, while non-frangible items are not reduced to said size;   b) then performing a size-based separation of the reduced glass fragments from the non-frangible items;   c) then washing the reduced glass fragments;   d) then drying the washed glass fragments; and   e) then grinding the dried glass fragments into a powder in a mill, said mill having a non-metallic surface lining a grinding chamber of said mill such that the dried glass fragments and the white powder are in contact with said non-metallic surface of said mill while said mill is grinding the dried glass, wherein said non-metallic surface does not impart a non-white discoloration to the powder during grinding such that the resulting powder has a brightness of at least 77 using the ASTM E 313 standard practice.   
     
     
         32 . A white glass powder according to  claim 31 , wherein:
 said white powder has a brightness of 77 to 80 the ASTM E 313 standard practice.   
     
     
         33 . A white glass powder according to  claim 31 , wherein:
 said non-metallic surface is stone.   
     
     
         34 . A white glass powder according to  claim 33 , wherein:
 said stone is quartz.   
     
     
         35 . A white glass powder according to  claim 31 , wherein:
 said grinding includes grinding in said grinding chamber with grinding media, said grinding media having a non-metallic surface.   
     
     
         36 . A white glass powder according to  claim 35 , wherein:
 said grinding media has a ceramic surface.   
     
     
         37 . A white glass powder according to  claim 36 , wherein:
 said grinding media are ceramic cylinders.   
     
     
         38 . A white glass powder according to  claim 31 , further comprising:
 classifying said white glass powder with a classifier that separates the white glass powder from remaining larger glass particulate,
 said classifier lined with a non-metallic material along a pathway through which said glass powder is moved during the separation. 
   
     
     
         39 . A white glass powder according to  claim 38 , wherein:
 said classifier is an air classifier.   
     
     
         40 . A white glass powder manufactured from a stream of post-consumer mixed-color waste glass containing organic contaminants and items of non-frangible materials, said white glass powder being free of organic contaminants and non-frangible materials, at least 60 percent of said white glass powder having a particle size not exceeding 325 mesh, and said white glass powder having a brightness of at least 77 using the ASTM E 313 standard practice. 
     
     
         41 . A white glass powder according to  claim 40 , wherein:
 said white powder has a brightness of 77 to 80 the ASTM E 313 standard practice.