Developments to Watch
MAKING METAL WITHOUT MAKING AN AWFUL MESS
Producing metal is a dirty business. Noxious sulfur, chlorine, or carbon gases spew from metalmaking furnaces. The air pollution comes from the way the metal is extracted: Ironmaking consumes a ton of carbon per ton of metal. And titanium is extracted using chloride salts and another metal, manganese. Now, a Massachusetts Institute of Technology researcher has a process to yield high-quality metals, with just oxygen as its chief byproduct.
The idea, called pyroelectrolysis, superheats the metal ores at temperatures as high as 1,700C. The heat shatters the chemical bonds without the use of sulfur or chloride salts. The new process also saves nearly two-thirds of the energy consumed during titanium processing, says Donald R. Sadoway, MIT materials science professor.
While he is optimistic about the new approach, Sadoway concedes that some hurdles remain. For one thing, carbon is still a key component of the electrodes used to heat some ores. He's hopeful that an advanced ceramic will be found to replace it. Faradaics Inc., a venture-capital backed company, has already been formed to raise financing for Sadoway's research. EDITED BY NAOMI FREUNDLICH