Steel From The Scrap Heap, On The Cheap
The old auto junkyard ain't what it used to be. Since the early 1980s, auto makers increasingly used galvanized steel to build rust-resistant cars. But that has created a new problem. Argonne National Laboratory engineer Edward J. Daniels says studies show that recycling galvanized scrap from autos and trucks costs a hefty $50 per ton, including environmental-control systems to capture the steel's toxic zinc coating.
Argonne and Canadian waste-management company Metal Recovery Industries Inc. in Hamilton, Ont., have developed a degalvanizing process that they say can slash these costs. Scrap is put into vats of sodium hydroxide. When an electric current is applied, the zinc collects on an electrode, where it can be removed easily. The process should allow the steelmakers to use more galvanized scrap in place of primary ores. That could save the equivalent of 9 million barrels of oil annually, says Daniels. Metal Recovery hopes to open a pilot facility in East Chicago, Ind., by mid-1992.