China currently manufactures half of the world’s iron and steel through a process that leaves enormous amounts of waste, or slag, to accumulate in landfills or in stockpiles out in the open where its toxic elements may cause environmental and health problems. In partnership with a major iron and steel company in China, two Columbia engineering researchers hope to repurpose some of this slag for use in a range of industries, including paper, plastic, paint, cement, oil, and gas.
In late December 2016, executives from China’s Baotou Iron and Steel (Group) Co. visited the Columbia Engineering lab of Ah-Hyung (Alissa) Park and Xiaozhou (Sean) Zhou to see the operation of a prototype processing unit designed by Park and Zhou to repurpose slag. Their goal is to turn wastes of steel and iron manufacturing into reusable materials through a chemical process that integrates the processes of mineral carbonation and rock weathering. They also hope to reduce overall carbon emissions by using industrially emitted carbon dioxide (CO2) as one of the reactants.
“We are working with Baotou Steel on an exciting project that uses our carbon sequestration technology to treat their iron and steel slag,” says Park, associate professor of earth and environmental engineering and chemical engineering and director of the Lenfest Center for Sustainable Energy. “The techniques we’ve developed have the potential to make iron and steel manufacturing substantially more sustainable—not only in China but globally.”
https://engineering.columbia.edu/news/manufacturing-waste-valuable-materials