High-Carbon Fly Ash Filler for the Manufacturing of Low-Cost Commercial Thermoplastic

Although recent pollution-control measures have successfully reduced NOX and mercury in flue emissions during coal combustion, these measures have led to a substantial increase in the amount of unused fly ash containing high carbon levels. The Portland cement industry, the largest consumer of fly ash, can only utilize fly ash with loss-on-ignition values less than 6% (although in practice the value is less than 2%). As a result, large amounts of high-carbon fly ash is being placed in land fills. Therefore, new commercial uses of the fly ash need to be developed. This project will develop technology to incorporate the high-carbon fly ash as a filler material in commercial thermoplastic composite extrusions, currently used in the construction and building industries. In this approach, a co-extrusion process will be used to cover the thermoplastic/fly ash composite with a thin outside coating, making irrelevant any carbon-related discoloration of the composite. In Phase I, the particle size of the fly ash will be optimized to improve the mechanical properties of the thermoplastic materials. Composites containing high-carbon fly ash will be extruded using varying experimental parameters. The composites also will be microstructurally and mechanically characterized. Commercial Applications and Other Benefits as described by the awardee: Thermoplastic composite molding containing high carbon materials should be suitable for quick introduction into the commercial building market. Composites containing inexpensive fly ash fillers could be used as water and sewer pipes, plumbing fixtures, conduits, flooring, roofing membranes, electrical cables, and interior moldings. Other applications include automotive components (truck bed liners, grills, wheel covers, bumpers, etc.), small and large appliances, electronic housings, luggage, credit cards, toys, and fencing materials. In addition, the utilization of high-carbon fly ash in thermoplastic composites also would help alleviate the large amounts of fly ash being land filled.