Method converts corn stover into basic sugars that feed metal-mining bacteria that extract rare earth metals from waste materials.
March 16, 2018
A new biochemical leaching process has been developed that uses corn stover as feedstock and recovers valuable rare earth metals from electronic waste, according to an announcement from the U.S. Department of Energy's Ames Laboratory in Ames, Iowa.
While corn and its byproducts can be used for high-tech applications ranging from bioplastics to ethanol, using corn stover for what is essentially a mining process may seem like a stretch many, but the new process does use stover as a key ingredient, the Ames Lab said.
The research was directed by the U.S. Department of Energy’s Critical Materials Institute (CMI) headquartered at the Ames Laboratory on the Iowa State University campus, and carried out by scientists at Idaho and Lawrence Livermore national laboratories and Purdue University.
David Reed, Yoshiko Fujita and Vicki Thompson hail from Idaho National Laboratory’s biological and chemical processing department and are researchers for CMI. They are part of a CMI team whose work is devoted to finding a way to tackle a growing environmental and manufacturing supply problem: the ever-increasing amount of electronic waste, like discarded cell phones and hard drives and the potential for recovering and recycling high-demand, rare-earth metals to be used again in manufacturing.
Hydrometallurgy is a liquid chemical process used to extract metals from ores, recycled or residual materials, the Ames Lab explained, but traditional leaching methods already in use by the mining industry are not a great choice for recycle and recovery methods for a number of reasons, said Thompson, who is a distinguished staff engineer at the Idaho National Laboratory.