A novel approach to paint sludge recycling: Reclaiming of paint sludge components as ceramic composites and their applications in reinforcement of metals and polymers

About 15 × 106 lbs of paint sludge, produced every year at Ford plants, is disposed of in landfills. An economical alternative to this disposal method, which reclaims or recycles components of paint sludge, is highly desirable to preserve valuable natural resources. Here, we describe an alternative to landfill disposal whereby paint sludge is converted into ceramic composites that can be used as reinforcing materials. The conversion of paint sludge to ceramic composite, I/N2/600, is achieved by pyrolysis under a nitrogen atmosphere. Two additional composites, labeled I/N2/1000 and I/NH3/1000, respectively, are prepared by sintering I/600 at 1000 °C under N2 and NH3. All three composites contain crystalline CaTiO3, BaTiO3, TiO2, amorphous alumina, and carbon. I/NH3/1000 contains an additional crystalline phase of titanium nitride. The application of these composites as reinforcing materials is demonstrated in the fabrication of representative metal matrix composites (MMC's) and reinforced plastic components.