HOUGHTON, MI--Researchers at Michigan Technological University are developing ways to use wastes from the aluminum industry to manufacture a variety of commercially valuable products.

"The aluminum industry produces approximately a million tons of waste by-product from its domestic smelting process, " said Dr. J. Y. (Jim) Hwang, director of the Institute of Materials Processing (IMP) and associate professor of mining engineering at Michigan Tech. "This waste by-product is called salt cake and is skimmed off for disposal during the smelting process. Getting rid of the salt cake costs aluminum producers millions of dollars in land filling and exposes them to environmental liabilities as well."

Hwang said he and his colleagues view salt cake not as a waste product, but as raw material that with further processing can be used to create value-added products that economically enhance the bottom line of the aluminum industry.

"We are developing a technology to divert salt cake into valuable feed stock materials for the manufacturing of concrete products such as lightweight masonry, foamed concrete, and mine backfill grout," explained Hwang. "By using the unique properties inherent in the aluminum salt cake, we can make this by-product function as a foaming (air entraining) agent and as fine aggregate for use in concrete."

Hwang said the new technology will benefit the aluminum, concrete, mining, and construction industries.

"The aluminum industry will improve its competitiveness from increased recovery of aluminum metal and release from its disposal burden and future liability threat," he explained. "The concrete industry is facing a growing building construction demand, especially in the lightweight concrete segment, and in the national overhaul of transportation infrastructure. The incoming processed aluminum smelting by-products will not only ease the concrete industry's material supply pressure, but will
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Contact: Dr. Jim Hwang
jhwang@mtu.edu
906-487-2600
Michigan Technological University
19-Feb-1999