Moving away from the conservative ways of converting food waste into something productive like energy or heat, Colorado School of Mines has created minerals out of the waste. Using food wastes such as rotten banana peels, eggshells and rice husks, the team created a 60-gram piece of crystal-clear glass.
"I mean, this was rotten garbage," Materials engineer Ivan Cornejo told Denver Post.
The process of converting waste into minerals is quite simple for the Colorado scientists. Once the garbage has been collected; it is grounded in blenders, dried and then crushed into fine white powder containing pure minerals, such as silica and oxides. An oven, heated to 3,000 degrees, melts the silica powder into a molten red substance. The red-hot liquid then cools to gold, white and eventually forms a clear glass.
Cornejo said that scientists and researchers now need not dig Earth's crust to meet the growing global demands for silica and other ingredients necessary for industrial goods. The team predicts that the volumes of food waste generated currently worldwide, is sufficient to meet the global demand for glass, which requires 36 million tons of silica.
"These mines are mostly open-pit mines all over the world. Silica is coming from Brazil and China,"said Cornejo. "There's no reason to continue mining, destroying the environment, when we can find many of the materials we need from waste."
Now, the Colorado team is now working on a new kind of waste - peanut shells, coffee grounds, and avocado seeds. They will be then working on developing minerals from cafeteria, feedlot and farm waste.
"This opens a new way of thinking about food waste," Cornejo said. "You allow people to eat what they have to eat. Then you use their waste to make unique materials."
