Production of glass powder from waste glass, and products made using the same, especially concrete

• US 7,413,602 B2
• Filed: 12/16/2004
• Issued: 08/19/2008
• Est. Priority Date: 12/16/2004
• Status: Active Grant

• Current Assignee: Urban Mining Industries LLC
• Original Assignee: Empire Resource Recovery LLC
• Inventors: Kracko, Elliot, Grasso, Patrick S. Sr., Grasso, Louis P. Jr., Grasso, Louis P. Sr., Andela, Cynthia A., Acampora, Ralph J.
• Primary Examiner(s): MARCANTONI, PAUL D
• Application Number:
  US11/012,726
• Publication Number:
  US 20060130707A1
• Time in Patent Office: 1,342 Days
• Field of Search: 106/716, 106/745, 241/24.1, 241/24.3, 241/29
• US Class Current: 106/716
• CPC Class Codes: B02C 21/00 Disintegrating plant with or without drying of the material for grain B02C9/04
• CPC Class Codes: B02C 23/08 Separating or sorting of material, associated with crushing or disintegrating B02C23/18 takes precedence ; beater mills combined with sifting devices B02C13/13, B02C13/14; for tumbling mills B02C17/1835
• CPC Class Codes: C04B 14/22 Glass ; Devitrified glass
• CPC Class Codes: C04B 20/0076 characterised by the grain distribution
• CPC Class Codes: C04B 20/02 Treatment
• CPC Class Codes: C04B 20/026 Comminuting, e.g. by grinding or breaking; Defibrillating fibres other than asbestos
• CPC Class Codes: C04B 28/04 Portland cements

Abstract

A clean dry 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 subsatantial 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 glass powder of uniform particle size.

Claims

1. A process for the production of concrete, comprising as a pozzolanic constituent a proportion of glass powder produced by processing a stream of post-consumer waste glass containing items of non-frangible materials, comprising the following steps, performed in the sequence given:

producing a dry glass powder comprising particles of which at least a major fraction are of size 325 mesh or finer, and containing no more than about 2% moisture, by;

pulverizing the stream of post-consumer waste glass containing non-frangible constituents such that glass in said stream is reduced to fragments of average maximum size ⅛

inch or less;

while non-frangible items are not reduced to said size, and performing a size-based separation of said reduced glass fragments from said non-frangible items;

washing said reduced glass fragments, to separate plastic and paper fragments therefrom, and to remove organic contaminants therefrom;

drying the washed glass fragments to a moisture content of no more than about 2% by weight; and

grinding the dried glass fragments into a powder, using a ball mill and a size-based classifier in a continuous ball milling and size-based classification process, wherein the glass fragments having been ground into particles are withdrawn from said ball mill and conveyed to said size-based classifier, with particles over a maximum average particle size being returned to said ball mill for further grinding, and the remainder being separated so as to form a powder, such that at least about 60% of the particles of said powder are of no more than 325 mesh particle size; and

mixing said glass powder with a larger quantity of Portland cement, aggregate materials, and water, said glass powder serving as a pozzolan, to form concrete.

2. The process of claim 1, wherein the proportion of said glass powder to Portland cement in said mixture is no more than about 40:

60 by weight.

3. The method of claim 1 wherein said steps of pulverizing and performing size-based separation is performed using a multi-flail pulverizer for reduction of glass in said waste stream to fragments and a trommel for size-based separation of glass fragments from larger non-frangible items.

4. The method of claim 1, wherein said step of washing reduced glass fragments is performed using multiple successive steps of dipping said fragments into a water bath and removing said fragments from said bath employing an auger conveyor.

5. The method of claim 1, wherein said step of drying said washed fragments is performed using a fluidized bed dryer, wherein said fragments are propelled upwardly by a stream of hot air.