CalStar Products Inc. plans to open a factory next month to make bricks from fly ash, a byproduct of coal burning. It claims to use roughly 85% less energy than traditional clay brick manufacturing, with an equivalent reduction in carbon-dioxide emissions.
The process for making clay bricks—mining clay, forming it into bricks and firing in kilns using coal or natural gas—has remained largely unchanged for decades, though manufacturers have made improvements to reduce environmental impacts.
CalStar forms its bricks from fly ash—a gray, chalky byproduct of burning coal— and a proprietary stew of chemicals. During eight hours of steam baths, the calcium in the fly ash hardens, making bricks that look, feel and act like their clay counterparts, Mr. Kumar says.
CalStar says the bricks are designed to meet standards set by ASTM International, a standards-setting organization, for things like strength, durability and water absorption—and will be installed in buildings for the first time early next year. CalStar says the bricks will be priced competitively with commercial clay bricks. In Chicago, for instance, its bricks will sell for 53 cents apiece on average, compared with 55 cents on average per commercial clay brick, Calstar says.
