Philadelphia recycler creates aggregate from mixed glass

A business recently opened a plant in the former Eddystone locomotive factory in Philadelphia to turn municipal curbside glass into a lightweight construction material, a report by the Philadelphia Inquirer says. AeroAggregates LLC opened the plant in early 2017.

AeroAggregates creates foamed glass aggregate from the curbside mixed glass. The report says the aggregate resembles crushed rock and serves a similar purpose in construction projects, but the manufactured material weighs 85 percent less than stone.

The report says European municipalities use a form of AeroAggregates' product in road building and bridge abutments, where a heavier fill material—such as the traditional stone—would compress soft soils or crush underground utilities. Foamed glass also has insulating qualities and can be used in green roofs and gardens.

According to the report, Archie Filshill, chief executive and co-founder of AeroAggregates, says researchers from Drexel University in Philadelphia and Lafayette College in Easton, Pennsylvania, are developing a concrete using the foamed glass aggregate that can be used in nonstructural applications, such as poured concrete floors.

The glass is crushed into a powder and mixed with silicon carbide. The mixture then passes through a 60-foot-long 180-degree-Fahrenheit kiln, the newspaper reports. The silicon carbide produces carbon bubbles and makes the mixture rise while melting. The process takes around 40 minutes. The material then cracks into 2-inch pieces while cooling.

Each kiln produces 80,000 cubic yards of the material per year using 12,000 tons of mixed glass, the newspaper reports.

Filshill, co-founder and company President Thomas McGrath and Chief Financial Officer Robert Schoen have pitched using the material to several state highway engineers. The report says, so far, transportation departments in Pennsylvania, New Jersey, Maryland, Virginia and New York have given preliminary approval. The Pennsylvania Department of Transportation (PennDot) already has used the material for a reconstruction project at the Navy Yard and plans to use it in a ramp project.

AeroAggregates has a contract to supply 30,000 cubic yards of its material in 2018 for a bridge project in Kearny, New Jersey, according to the report.

The company says it is ordering a second kiln that will be installed in early 2018. The kiln was financed by Closed Loop Partners, New York City, through an investment fund underwritten by $100 million in corporate money.