COLUMBIA, Mo., May 29 (UPI) -- U.S. scientists have developed bricks made from fly ash -- the waste produced by coal-fired power plants -- that might be even safer than predicted.
Instead of leaching tiny amounts of mercury as some researchers predicted, the bricks apparently do the reverse, pulling minute amounts of the toxic metal from ambient air.
"Manufacturing clay brick requires kilns fired to high temperatures," said Henry Liu, president of the Freight Pipeline Co. of Columbia, Mo., which developed the new bricks. "That wastes energy, pollutes air and generates greenhouse gases that contribute to global warming. In contrast, fly ash bricks are manufactured at room temperature ... and don't contribute to air pollution or global warming."
Supported by the National Science Foundation, Liu made fly ash bricks more durable by engineering them to resist freezing and thawing due to weather. Liu is now working to test the brick material's safety and prepare it for market.
While researchers need to study the bricks further to determine how the mercury adsorption occurs and how tightly the metal is trapped, the new findings suggest the bricks will not have a negative impact on indoor air quality.
