14 DAY TRIAL // A new discovery shows that bricks made from fly ash are very stable and much safer than initially thought. When they were first discovered, many theorized that these special bricks would leak small amounts of mercury into the atmosphere, thus posing a major threat for humans.
A team of researchers, led by Henry Liu, a longtime National Science Foundation (NSF) awardee and the president of Freight Pipeline Company (FPC), developed the new bricks and found out that, on the contrary, the bricks are pulling minute amounts of the toxic metal out of ambient air.
Fly ash is one byproduct of the coal combustion process and represents part of the inorganic material in coal, being made up of molten minerals, such as clay, quartz and feldspar that solidify in the moving air stream leaving the combustion chamber.
Every year, almost 45 million tons of fly ash go to waste and only around 25 million tons are recycled. Used as additive in cements, fly ash is beneficial for decreasing the reactivity of the cement and its cracking, as the spherical shape of the material acts like ball bearings.
"Manufacturing clay brick requires kilns fired to high temperatures," said Liu. "That wastes energy, pollutes air and generates greenhouse gases that contribute to global warming. In contrast, fly ash bricks are manufactured at room temperature. They conserve energy, cost less to manufacture, and don't contribute to air pollution or global warming."
The new applications of the fly ash are called FPC bricks and resemble the clay ones and even exceed construction-material standards, resisting freezing and thawing due to weather.
The innovative bricks using the residual fly ash are considered high quality building materials by the manufacturers that "will potentially decrease some of the negative environmental impact of coal-fired power generation while meeting increasing demands for greener building materials."