$1.5M GRANT TO EXPLORE INTEGRATED REUSE OF STEEL INDUSTRY BY-PRODUCTS A new research project led by Cornell University (New York, US) will seek an integrated approach to turning by-products including flue dusts, sludge and co-products , such as various metallurgical slags into valuable materials using a $1.5 million from the U.S. Department of Energy. Co-Product1 (by-product2,3) – means a product that is intentionally generated during the manufacturing process or chemical reaction(s) of the primary product or process. Co-product may also be characterised as essential to the primary product or process, having a critical influence on the properties of the primary product, e.g. the manufacture of crude steel. Iron and Steel Slags are essential co-products to the production of pig iron and steel. Common uses are slag cement and air-cooled iron blast furnace slag and steel slag aggregates. https://www.asa-inc.org.au/knowledge/technical-literature/terminology [accessed May 2021]
The steel industry has sought methods to use the co-products from steel and other manufacturing processes, however, these efforts have a heavy focus on processing independently of each other. A group of academic and industry experts led by A/Prof Greeshma Gadikota, in the School of Civil and Environmental Engineering, proposes a new approach that would synergise the recycling of industrial steel by improving the recovery and quality of co-products using carbon dioxide generated during the iron and steelmaking process. The research project is titled; “Integrated Reuse and Co-Utilization of Slag, Sludge and Dust with Inherent Heavy Metal Capture and Nanoscale Calcium Carbonate Production as an Enhanced Fluxing Agent in Steel Plants (INSIGHT).” Explaining the methods involved in the project, Gadikota says, “Our interest is in developing holistic solutions that harness all the metal-bearing residues and carbon dioxide generated in iron and steel making processes to produce nano-scale calcium carbonate and iron oxide and remove [trace] heavy metals”. Gadikota continued, “A key differentiator of this approach from existing pathways is the use of regenerable solvents for capturing carbon dioxide directly from flue gas to produce nano-scale carbonates at much lower temperatures in a process-intensified manner.” The group, including investigators from Columbia University, research and development firm Reaction Engineering International, and engineering management company HATCH, will focus on three specific areas:
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The synthesis of uniform nanoscale calcium carbonate from slag using regenerable solvents. Uniform nanoscale particles can be used to enhance the reaction kinetics and predictability of steel manufacturing processes compared to the conventional use of limestone.
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Iron oxide recovered from the alkaline residues will be reused in the steel making process.
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Recovered silica will be functionalized to separate the undesirable metal constituents such as lead, copper, and nickel.
The team will investigate the overall efficiency of current steel manufacturing processes and reduce the number of materials that need to be treated and landfilled. There are other economic benefits to adopting this approach according to Gadikota, such as US Federal Tax credits that reward companies for capturing and reusing carbon dioxide. Members of the group have previously worked together to advance technologies for carbon dioxide capture, conversion and storage, and hold several key patents that will enable the research funded by the new grant. The new approach also includes principles of the circular economy, with Gadikota providing evidence in research to suggest, “This exciting project directly addresses our societal mission of meeting our resource needs in an environmentally sustainable manner,” said Gadikota. “Iron and steel use is ubiquitous in our infrastructure. INSIGHT is a unique opportunity to engage and train our students in developing innovative technologies that are central to our ability to live,” said Gadikota.
Credit: Cornell University
www.asa-inc.org.au
connections July 21 | 04
